inventory management ii lot sizing lecture 5 esd.260 fall 2003 caplice
TRANSCRIPT
Inventory Management II Lot Sizing
Lecture 5ESD260 Fall 2003
Caplice
Outline
EOQ Model
Sensitivity Analysis
Discounting1048708
All Units1048708
Incremental1048708
One Time Special
MIT Center for Transportation amp Logistics - ESD260 2 copy Chris Caplice MIT
Assumptions Basic EOQ Model Demand1048708 Constant vs Variable1048708 Known vs Random1048708 Continuous vs Discrete Lead time Instantaneous1048708 Constant or Variable (deterministicstochastic) Dependence of items 1048708 Independent Correlated1048708 Indentured 1048708 Review Time Continuous vs Periodic Number of Echelons1048708 One vs Many Capacity Resources1048708 Unlimited vs Limited
Discounts1048708 None1048708 All Units or Incremental Excess Demand1048708 None1048708 All orders are backordered1048708 Lost orders1048708 Substitution Perishability1048708 None1048708 Uniform with time Planning Horizon1048708 Single Period1048708 Finite Period1048708 Infinite Number of Items1048708 One1048708 Many
MIT Center for Transportation amp Logistics - ESD260 3 copy Chris Caplice MIT
Notation
TC = Total Cost (dollartime) D = Average Demand (unitstime) Co = Ordering Cost (dollarorder) Ch = Holding Cost (dollarsdollars heldtime) Cp = Purchase Cost (dollarsunit) Q = Order Quantity (unitsorder) T = Order Cycle Time (timeorder)
MIT Center for Transportation amp Logistics - ESD260 4 copy Chris Caplice MIT
Lot Sizing Many Potential Policies
MIT Center for Transportation amp Logistics - ESD260 5 copy Chris Caplice MIT
Inve
nto
ry O
n H
and
Time
Objective Pick the policy with the lowest total cost
I(t)
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Outline
EOQ Model
Sensitivity Analysis
Discounting1048708
All Units1048708
Incremental1048708
One Time Special
MIT Center for Transportation amp Logistics - ESD260 2 copy Chris Caplice MIT
Assumptions Basic EOQ Model Demand1048708 Constant vs Variable1048708 Known vs Random1048708 Continuous vs Discrete Lead time Instantaneous1048708 Constant or Variable (deterministicstochastic) Dependence of items 1048708 Independent Correlated1048708 Indentured 1048708 Review Time Continuous vs Periodic Number of Echelons1048708 One vs Many Capacity Resources1048708 Unlimited vs Limited
Discounts1048708 None1048708 All Units or Incremental Excess Demand1048708 None1048708 All orders are backordered1048708 Lost orders1048708 Substitution Perishability1048708 None1048708 Uniform with time Planning Horizon1048708 Single Period1048708 Finite Period1048708 Infinite Number of Items1048708 One1048708 Many
MIT Center for Transportation amp Logistics - ESD260 3 copy Chris Caplice MIT
Notation
TC = Total Cost (dollartime) D = Average Demand (unitstime) Co = Ordering Cost (dollarorder) Ch = Holding Cost (dollarsdollars heldtime) Cp = Purchase Cost (dollarsunit) Q = Order Quantity (unitsorder) T = Order Cycle Time (timeorder)
MIT Center for Transportation amp Logistics - ESD260 4 copy Chris Caplice MIT
Lot Sizing Many Potential Policies
MIT Center for Transportation amp Logistics - ESD260 5 copy Chris Caplice MIT
Inve
nto
ry O
n H
and
Time
Objective Pick the policy with the lowest total cost
I(t)
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Assumptions Basic EOQ Model Demand1048708 Constant vs Variable1048708 Known vs Random1048708 Continuous vs Discrete Lead time Instantaneous1048708 Constant or Variable (deterministicstochastic) Dependence of items 1048708 Independent Correlated1048708 Indentured 1048708 Review Time Continuous vs Periodic Number of Echelons1048708 One vs Many Capacity Resources1048708 Unlimited vs Limited
Discounts1048708 None1048708 All Units or Incremental Excess Demand1048708 None1048708 All orders are backordered1048708 Lost orders1048708 Substitution Perishability1048708 None1048708 Uniform with time Planning Horizon1048708 Single Period1048708 Finite Period1048708 Infinite Number of Items1048708 One1048708 Many
MIT Center for Transportation amp Logistics - ESD260 3 copy Chris Caplice MIT
Notation
TC = Total Cost (dollartime) D = Average Demand (unitstime) Co = Ordering Cost (dollarorder) Ch = Holding Cost (dollarsdollars heldtime) Cp = Purchase Cost (dollarsunit) Q = Order Quantity (unitsorder) T = Order Cycle Time (timeorder)
MIT Center for Transportation amp Logistics - ESD260 4 copy Chris Caplice MIT
Lot Sizing Many Potential Policies
MIT Center for Transportation amp Logistics - ESD260 5 copy Chris Caplice MIT
Inve
nto
ry O
n H
and
Time
Objective Pick the policy with the lowest total cost
I(t)
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Notation
TC = Total Cost (dollartime) D = Average Demand (unitstime) Co = Ordering Cost (dollarorder) Ch = Holding Cost (dollarsdollars heldtime) Cp = Purchase Cost (dollarsunit) Q = Order Quantity (unitsorder) T = Order Cycle Time (timeorder)
MIT Center for Transportation amp Logistics - ESD260 4 copy Chris Caplice MIT
Lot Sizing Many Potential Policies
MIT Center for Transportation amp Logistics - ESD260 5 copy Chris Caplice MIT
Inve
nto
ry O
n H
and
Time
Objective Pick the policy with the lowest total cost
I(t)
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Lot Sizing Many Potential Policies
MIT Center for Transportation amp Logistics - ESD260 5 copy Chris Caplice MIT
Inve
nto
ry O
n H
and
Time
Objective Pick the policy with the lowest total cost
I(t)
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
What is the total cost
TC = Purchase + Order + Holding + Shortage Cost
Which costs are relevant Purchase Costs
Ordering Costs
Holding Costs
Shortage Costs
MIT Center for Transportation amp Logistics - ESD260 6 copy Chris Caplice MIT
02
( ) h pQD
QTC Q C C C
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Economic Order Quantity (EOQ)
0[ ]
2
h pC D C C QTC Q
Q
02
h p
DCQ
C C
MIT Center for Transportation amp Logistics - ESD260 7 copy Chris Caplice MIT
0 2 h pTC DC C C
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Simple EOQ Example
Annual demand of widgets is 2000 The cost of ordering is $500 Widgets are procured for $50 each and are sold for $95 each Holding cost is estimated to be 25
What is the EOQ Total Cost and Cycle Time
Q = 400 units TC = $5000 year T = 020 years or 73 days
MIT Center for Transportation amp Logistics - ESD260 8 copy Chris Caplice MIT
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Total Cost versus Lot (Order) Size
MIT Center for Transportation amp Logistics - ESD260 9 copy Chris Caplice MIT
Lot Size
Ann
ual
Cos
t
Annual Cost vs Order Quantity
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
The Effect of Non-Optimal Q
Q DCoQ ChCpQ2 TC
2000 $500 $12500 $13000
500 $2000 $3125 $5125
400 $2500 $2500 $5000
200 $5000 $1250 $6250
20 $50000 $125 $50125
MIT Center for Transportation amp Logistics - ESD260 10 copy Chris Caplice MIT
So how sensitive is TC to Q
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Sensitivity of EOQ
How does TC change with Q
02
( ) h pQD
QTC Q C C C
0( ) 2 p hTC Q C C C D
( ) 1
( ) 2
TC Q Q Q
TC Q Q Q
MIT Center for Transportation amp Logistics - ESD260 11 copy Chris Caplice MIT
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Sensitivity of EOQ
Sensitivity TC wrt Q
MIT Center for Transportation amp Logistics - ESD260 12 copy Chris Caplice MIT
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Sensitivity of EOQ
What if our estimate of demand was off E = Actual Demand Estimated Demand
Qrsquo = Estimated EOQ
Q = Actual EOQ given actual demand that occurred
D ActualE
D Estimate 02
h p
D CQ
C C
QE
Q
1
2
TC E
TC E
MIT Center for Transportation amp Logistics - ESD260 13 copy Chris Caplice MIT
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Sensitivity of EOQ to Parameter Error
So for Drsquo = 2000 unitsyear if the
actual demand was hellip
D E QQ TCTC
200 010 032 174
1000 050 071 106
1500 075 087 101
1800 090 095 100
2000 100 100 100
3000 150 122 102
4000 200 141 106
20000 1000 316 174
MIT Center for Transportation amp Logistics - ESD260 14 copy Chris Caplice MIT
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Insights from EOQ
There is a direct trade off between lot size and total inventory
Total cost is relatively insensitive to changes
Very robust with respect to changes in Q ndashrounding of order quantities1048708 D ndasherrors in forecasting1048708
Ch Co Cp ndasherrors in cost parameters
Thus EOQ is widely used despite its highly restrictive assumptions
MIT Center for Transportation amp Logistics - ESD260 15 copy Chris Caplice MIT
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Introduce Discounts to Lot Sizing Types
Types of discounts1048708
All units discount1048708
Incremental discount1048708
One time only discount
How will different discounting strategies impact your lot sizing decision
MIT Center for Transportation amp Logistics - ESD260 16 copy Chris Caplice MIT
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
All Units Discount
Unit Price
[Cpi ]
Price Break Quantity
[PBQI]
$5000 0
$4500 500
$4000 1000
MIT Center for Transportation amp Logistics - ESD260 17 copy Chris Caplice MIT
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
All Units Discount
Need to introduce purchase cost into TC function
MIT Center for Transportation amp Logistics - ESD260 18 copy Chris Caplice MIT
0
2
h pipi pi
C D C C QTC Q C DC
Q
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 19 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
All Units Discount
Annual Costs
MIT Center for Transportation amp Logistics - ESD260 20 copy Chris Caplice MIT
Do
llar
s
Lot Size
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
All Units Discount MethodSame Example
D=2000 Unitsyr
Ch=25
Co=$500
CpiPrice Breaks $50 for 0 to lt500 units $45 for 500 to lt1000 units $40 for 1000+ units
MIT Center for Transportation amp Logistics - ESD260 21 copy Chris Caplice MIT
1 Cpi $4000 $4500 $5000
2 PBQ 1000 500 0
3 EOQ[Cpi] 447 421 400
4 Qpi 1000 500 400
5 DCpi $80000 $90000 $100000
6 C0DQpi $1000 $1000 $2500
7 ChCpiQpi2 $5000 $5000 $2500
8 TC[Qpi] $86000 $94812 $105000
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Incremental Discount
Treatment of the Incremental DiscountCost of Each Unit in the Lot
Cost of the Unit
Lot UnitMIT Center for Transportation amp Logistics - ESD260 22 copy Chris Caplice MIT
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 23 copy Chris Caplice MIT
Annual Cost
Lot Size
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
Incremental Discount
MIT Center for Transportation amp Logistics - ESD260 24 copy Chris Caplice MIT
Index i=3 i=2 i=1
1 Cpi $4000 $4500 $5000
2 PBQi 1000 500 0
3 Fi $7500 $2500 $0
4 EOQ[Cpi] 1789 1033 400
5 Qpi 1789 400
6 Cpe $4419 $5000
7 DCpe $8838457 $100000
8 CoDQpi $55897 $2500
9 (Ch C pe Qpi)2 $988250 $2500
10 TC[Qpi] $9882604 $105000
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 25 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 26 copy Chris Caplice MIT
Let 1048708 Cpg= One time deal purchase price ($unit)1048708 Qg= One time special order quantity (units)1048708 TCsp=TC over time covered by special purchase ($)
Then
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
One Time Discount
02
g gsp g pg g h pg
Q QTC Q D C Q C C C
D
MIT Center for Transportation amp Logistics - ESD260 27 copy Chris Caplice MIT
0
2 2
g ww w w gnsp g pg w p g w h pg h p
w
Q QQ Q Q QTC Q D C Q C Q Q C C C C C
D D Q
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
One Time Discount
p pg p wg
pg h pg
C C D C QQ
C C C
MIT Center for Transportation amp Logistics - ESD260 28 copy Chris Caplice MIT
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
- Slide 28
- Slide 29
-
One Time Discount
MIT Center for Transportation amp Logistics - ESD260 29 copy Chris Caplice MIT
A quick numerical example
D = 2000 units year Co= $50000 order Ch= 25 Cp= $5000 uni Q = 400 units TC = $500000 year
Cpg= $4500 unit Qg= 1333 Savings = $244825
- Slide 1
- Slide 2
- Slide 3
- Slide 4
- Slide 5
- Slide 6
- Slide 7
- Slide 8
- Slide 9
- Slide 10
- Slide 11
- Slide 12
- Slide 13
- Slide 14
- Slide 15
- Slide 16
- Slide 17
- Slide 18
- Slide 19
- Slide 20
- Slide 21
- Slide 22
- Slide 23
- Slide 24
- Slide 25
- Slide 26
- Slide 27
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