unit1 om
TRANSCRIPT
Operations Management (ME-601)
Prof. S. N. Varma
Ref.
Stevenson WJ; Operations Management; TMH
Hopp WJ and Spearman ML; Factory Physics; McGraw-Hill
Chary SN; Production and OM; TMH
Learning Objectives
Define the term operations management Compare and contrast service and manufacturing
operations Describe the operations function and the nature of
the operations manager’s jobBriefly describe the historical evolution of operations
managementIdentify current trends that impact operations
management
Operations ManagementOperations Management (OM) is defined as:
OM is management of input resources and the process of conversion to value added output of goods and/ or services to provide utility and satisfaction to customers.
The management of organization resources and systems/ processes that create/provide goods and/or services
OM affects: Organizations’ ability to competeEfficiency and effectiveness of non-profit organizationsNation’s ability to compete internationally
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The OrganizationThe Three Basic Functions
Actual functional division may be moree.g. Outsourcing, Info management(MIS) …
Organization
Finance Operations Marketing
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Value-Added Conversion Process
The operations function involves the conversion of inputs into outputs
InputsMoney, Man, Machine, Material,INFO
Transformation/Conversion
process
Outputs Goods Services
Control
Efficiency Feedback
Effectiveness FeedbackFeedback and control
Value added
Dr. S.N. VARMA
The Resources Recycle
TRANSFORMATION / PROCESSING SYSTEM OF THE ENTERPRISE
MONEY- LAND, BUILDING
EQUIPMEN, MACHINES
MANAGERS(PLAN ETC)
LABOUR (OPERATION)
RAW-MATERIAL
PRODUCT /SERVICES
CONSUMER
RE
VE
NU
E
GOVERNMENT
REGULATIONS
LOBBYING
CONSUMER-ADVOCACY
SUPPLIERSLABOUR
MANAGERSFINANCIAL INSTSTOCK-
HOLDERS
INPUTS PROCSSINGOUTPUTS
RISK MONEY
TAXESCOST
WAGES
INTEREST
SALARY
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Types of Operations
Operations ExamplesGoods Producing Farming, mining, construction,
manufacturing, power generationStorage/TransportationWarehousing, trucking, mail
service, moving, taxis, buses,hotels, airlines
Exchange Retailing, wholesaling, banking,renting, leasing, library, loans
Entertainment Films, radio and television,concerts, recording
Communication Newspapers, radio and televisionnewscasts, telephone, satellites
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Automobile assembly, steel making
Home remodeling, retail sales
Automobile Repair, fast food
Goods-services Continuum
Computer repair, restaurant meal
Song writing, software development
Goods Service
Surgery, teaching
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Value added Food Processor
Inputs Processing Outputs
Raw Vegetables Cleaning Canned vegetables Metal Sheets Making cans
Water CuttingEnergy CookingLabor PackingBuilding LabelingEquipment
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Value added Hospital Process
Inputs Processing Outputs
Doctors, nurses Examination Healthy patientsHospital Surgery
Medical SuppliesMonitoringEquipment MedicationLaboratories Therapy
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Manufacturing or Service?
Tangible Act
Key differences- Goods v/s Services
Characteristic Goods Service
OutputProduction and delivery time
TangibleDifferent-seq
IntangibleSame
Variability of input Low HighLabor content Low HighVariability of output Low High
Measurement of productivity Easy Difficult
Opportunity to correct problems High Low
Inventory High LowEvaluation of output Easier DifficultPatentable Usually Not usual
1-12
OM is a major component of SCM. decisions:Deciding where to locate facilities What type of layoutForecastingCapacity planningSchedulingManaging inventoriesAssuring qualityMotivating employeesMarketing and Distribution managementAnd more . . .
Scope of Operations Management
Shift in Jobs v/s National Development
Three Basic Area
Under developed
Developing
Developed
Agriculture 80% 40% 8%
Manufacturing
12% 40% 30%
Services 8% 20% 62%
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© 20e River, N.J. 07458 Prof. S N Varma 1-15
Development of Service Economy
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Year Mfg. Service45 79 2150 72 2855 72 2860 68 3265 64 3670 64 3675 58 4280 44 4685 43 5790 35 6595 25 7500 30 70
02 25 75
U.S. Manufacturing vs. Service Employment
0102030405060708090
45 50 55 60 65 70 75 80 85 90 95 00 02 05
Year
Per
cent
Mfg.
Service
Decline in Jobs, but they are importantWhy Decline in jobs? Due to success in mgt (objective)
Productivity: Increasing productivity allows companies to maintain or
increase their output using fewer workers
Outsourcing (win-win, divide and improve): Some mfg. work has been
outsourced to more productive companies.Importance of Farming/ Mfg.
Food is a primary physical need Mfg. - Over 30% jobs with lucrative salary
Mfg. - Accounts for over 70% of value of U.S. exports
Average full-time compensation in mfg. about 20% higher than average of all
workers
Manufacturing workers more likely to have benefits
Productivity growth in manufacturing in the last 5 years is more than double in
U.S. economy
Challenges of Managing ServicesService jobs are often less structured than
manufacturing jobsCustomer contact is higherWorker skill levels are lowerServices hire many low-skill, entry-level workersEmployee turnover is higherInput variability is higherService performance can be affected by
worker’s personal factors
Basic Product-Process matrix
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One of a Kind Low Volume
Multiple Products Moderate Volumes
Few Major ProductsHigh Volume
Commodity Products
Project
Job Shop
Batch
Line/ Mass Pr
Continuous Flow
Very Poor Fit(Unskilled)
Very Poor Fit(Genious)
Low ----------------VOLUME----------------- HighHigh --------Time between parts-------------- LowJumbled--Flow smoothness---------------- Smooth
Low
--
VA
RIE
TY
(pa
rts)
--
Hig
hLo
w
--P
roce
ss F
lexi
bilit
y-
Hig
hH
igh
--
Sta
ndar
diza
tion-
--
Low
Basic Plant Layouts
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Basic Processes
Layout Examples
Continuous Flow Production (Fluid)
Product piping Refinery, Sugar Commodities
Mass Production Product Layout, Connected mechanized material transfer, assembly lines
Automobile, TV, Packed Food
Batch Production Mixed Flow, Cellular Layout, Disconnected lines,
Watches, Drilling Rigs
Job-shop Prod., Jumbled Flow
Process Layout Tools,
Project work, Jumbled Flow
Site work layout Dams, Ships, Houses
Decision MakingSystem Design-Structural–capacity
–location
–arrangement of departments
–product and service planning
–acquisition and placement of
Equipments - project works
System operation- infrastructural
–Product mix–
Inventory, Shop Floor C
– Master Prod Schedule–
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-- Personnel
Forecast, Aggregate plan
--Demand synch, Pull, CONWIP
-- Quality assurance
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Use of Models in Decision MakingA model is an abstraction of reality.
What are the pros and cons of models?
Tradeoffs
1. Physical or Iconic models e.g. 3D-models of plane, car, bldg2. Analogue or schematic models e.g. graphs, contours, pie diagram3. Symbolic or mathematical models e.g. algebraic, differential
equation
Dr S. N. VARMA
Mathematical Models
Mathematical models: Deterministic models
Allocation: LPP, IPP, Goal Prog, TPP, Assignment, Sequencing, Network models; Deterministic Inventory models, Dynamic P Non linear prog.; Capital Investment;
Probabilistic models Forecasting Decision theory, games and competitive strategy. Queuing and waiting models Probabilistic Dynamic programming Probabilistic Inventory Replacement
Simulation and Meta-heuristics algorithms for non-LP and combinatorial optimization:
Tabu search, simulated annealing, Genetic A, DE, teacher learner algo.
Merits and Demerits of ModelingAdvantages of Modeling:
Easy to use, less expensiveRequire user to organize, define problem and analysis Increase understanding of the problemEnable “what if” questionsConsistent tool for evaluation and standardized formatPower of mathematics
Disadvantages of modeling:Quantitative information may be emphasized over qualitativeModels may be incorrectly applied and results misinterpretedUse of models does not guarantee good decisions
21-Feb-12 Prof. S.N. Varma 24
How models are used? Phases/ methodology of Modeling: -
1. Search, define and formulate problem, list alternatives to evaluate.
2. Make hypothesis, construct model and validate with the real system
3. Experiment and deduct results leading to model conclusion & theory
4. Evaluate alternatives & compare/ verify with real system attributes
5. Select best solution, establish controls and implement.
6. Post audit
Dr S. N. VARMA
Real System
Hypothesis and modeling
Model conclusions, theory
Real system attributes
Draw conclusions
Formulate/ Inductive generalize
Test theory, verify
Experiment, deductions
Validate,
revise
Implement
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Pareto Phenomenon• A few factors account for a high
percentage of the occurrence of some event(s).
• 80/20 Rule - 80% of problems are caused by 20% of the activities.
How do we identify the vital few?
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Business Operations Overlap
Operations
FinanceMarketing
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Operations Interfaces
Public Relations
Accounting
IndustrialEngineering
Operations
Maintenance
Personnel
Purchasing
Distribution
MIS
Legal
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Suppliers’ Suppliers
DirectSuppliers Producer Distributor Final
Consumer
Simple Product Supply Chain
Supply Chain: A sequence of activitiesAnd organizations involved in producingAnd delivering a good or service
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Stage of Production Value Added
Value of Product
Farmer produces and harvests wheat $0.15 $0.15
Wheat transported to mill $0.08 $0.23
Mill produces flour $0.15 $0.38
Flour transported to baker $0.08 $0.46
Baker produces bread $0.54 $1.00
Bread transported to grocery store $0.08 $1.08
Grocery store displays and sells bread $0.21 $1.29
Total Value-Added $1.29
A Supply Chain for Bread
Historical Evolution of OM
From craft production to Industrial revolution (1770’s)Scientific Management, Work Study (1911-FW Taylor)
Mass production Interchangeable partsDivision of labor
Human relations movement (1920-80)Ergonomics, fatigue (Gilberth)Hawthorn Experiment (Not illumination but Motivation- Elton Mayo)Need hierarchy, hygienic-motivating factors (Maslow, Hertzberg)Theory-X and theory-Y (Mc Gregory)Theory Z, JIT Lean Mfg., TQM (Ohno Taichi)
Decision models (1915, 1960-80’s)Influence of Japanese manufacturers, Outsourcing
Management and IT RevolutionTechnology: The application of scientific discoveries to
the development and improvement of goods and servicesProduct and service technologyProcess technologyInformation technology revolution
The Internet, ERP, e-business, e-commerce Management technologyGlobalizationManagement of supply chainsOutsourcingAgility
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-33
The Heritage of Operations Management
Division of labor (Adam Smith 1776 and Charles Babbage 1852)
Standardized parts (Whitney 1800)
Scientific Management (Taylor 1881)
Coordinated assembly line (Ford/Sorenson/Avery 1913)
Gantt charts (Gantt 1916)
Motion study (Frank and Lillian Gilbreth 1922)
Quality control (Shewhart 1924; Deming 1950)
Computer (Atanasoff 1938)
CPM/PERT (DuPont 1957)
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-34
The Heritage of O M -Contd
Material requirements planning (Orlicky 1960)
Computer aided design (CAD 1970)
Flexible manufacturing system (FMS 1975)
Baldrige Quality Awards (1980)
Computer integrated manufacturing (1990)
Globalization(1992)
Internet (1995)
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-35
Eli Whitney¨ Born 1765; died 1825¨ In 1798, received
government contract to make 10,000 muskets
¨ Showed that machine tools could make standardized parts to exact specifications¨ Musket parts could be used in
any musket© 1995 Corel Corp.
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-36
Frederick W. Taylor¨ Born 1856; died 1915¨ Known as ‘father of scientific
management’¨ In 1881, as chief engineer for
Midvale Steel, studied how tasks were done¨ Began first motion & time studies
¨ Created efficiency principles
© 1995 Corel Corp.
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-37
Taylor: Management Should Take More Responsibility for
Matching employees to right jobProviding the proper trainingProviding proper work methods and
toolsEstablishing legitimate incentives for
work to be accomplished
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-38
Frank & Lillian Gilbreth
¨ Frank (1868-1924); Lillian (1878-1972)
¨ Husband-and-wife engineering team
¨ Further developed work measurement methods
¨ Applied efficiency methods to their
home & 12 children! ¨ (Book & Movie: “Cheaper by the
Dozen,” book: “Bells on Their Toes”)
© 1995 Corel Corp.
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-39
¨ Born 1863; died 1947¨ In 1903, created Ford
Motor Company¨ In 1913, first used
moving assembly line to make Model T¨ Unfinished product
moved by conveyor past work station
¨ Paid workers very well for 1911 ($5/day!)
Henry Ford
‘Make them all alike!’
© 1995 Corel Corp.
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-40
W. Edwards Deming¨ Born 1900; died 1993¨ Engineer & physicist¨ Credited with teaching
Japan quality control methods in post-WW2
¨ Used statistics to analyze process
¨ His methods involve workers in decisions
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-41
Contributions FromHuman factorsIndustrial engineeringManagement scienceBiological sciencePhysical sciencesInformation science
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-42
Significant Events in OM Division of labor (Smith, 1776) Standardized parts (Whitney, 1800) Scientific management (Taylor, 1881) Coordinated assembly line (Ford 1913) Gantt charts (Gantt, 1916) Motion study (the Gilbreths, 1922) Quality control (Shewhart, 1924) CPM/PERT (Dupont, 1957) MRP (Orlicky, 1960) CAD and Flexible manufacturing systems (FMS) Manufacturing automation protocol (MAP) Computer integrated manufacturing (CIM)
Transparency Masters to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e
© 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 1-43
New Challenges in OMLocal or national
focusBatch shipmentsLow price bid
purchasingLengthy product
developmentStandard productsJob specialization
¨ Global focus¨ Just-in-time¨ Supply chain partnering¨ Rapid product
development, alliances¨ Mass customization¨ Empowered employees,
teams
From To
Ethical IssuesFinancial statementsWorker safetyProduct safetyQualityEnvironmentCommunityHiring/firing workersClosing facilitiesWorker’s rights
Factory Physics and dynamicsDefinitionsWorkstations: a collection of one or more identical machines.
Parts: a component, sub-assembly, or an assembly that moves through the workstations.
End Items: parts sold directly to customers; relationship to constituent parts defined in bill of material (BOM).
Consumables: bits, chemicals, gasses, etc., used in process but do not become part of the product that is sold.
Routing: sequence of workstations needed to make a part.
Order: request from customer.
Job: transfer quantity on the line.
Definitions (cont.)Throughput (TH): for a line, throughput is the average quantity
of good (non-defective) parts produced per unit time.
Work in Process (WIP): inventory between the start and endpoints of a product routing.
Raw Material Inventory (RMI): material stocked at beginning of routing.
Crib and Finished Goods Inventory (FGI): crib inventory is material held in a stock-point at the end of a routing; FGI is material held in inventory prior to shipping to the customer.
Mfg. Lead/ Cycle Time (CT): time between release of the job at the beginning of the routing until it reaches an inventory point at the end of the routing.
Customer Lead Time: Time between customer order and delivery
Definitions (cont.)
Definition: A manufacturing system is a goal-oriented network of processes through which parts flow.
Structure: Plant is made up of routings (lines), which in turn are made up of processes.
Focus: Factory Physics® is concerned with the network and flows at the routing (line) level.
ParametersDescriptors of a Line:
1) Bottleneck Rate (rb): Rate (parts/unit time or jobs/unit time) of the process center having the highest long-term utilization, thus slowest flow.
2) Raw Process Time (T0): Sum of the long-term average process times of each station in the line.
3) Congestion Coefficient (): A unit less measure of congestion.Zero variability case, a = 0.“Practical worst case,” a = 1.“Worst possible case,” a = W0.
Little’s lawThis is a non-congestion, steady-state system flow law:
Time in system/ cycle time, CT=WIP/rb
Insights:Fundamental relationshipSimple units transformationDefinition of cycle time (CT = WIP/TH)WIP is main reason for delays, not process variance (though exp.
process variance with high capacity utilization causes high WIP)
Relationship:Critical WIP (W0): WIP level in which a line having no congestion
would achieve maximum throughput (i.e., rb) with minimum cycle time (i.e., T0).
W0 = rb T0
The Penny-Fab-1 exampleCharacteristics:
Four identical in series.Each takes 2 hours per piece (penny).No variability.CONWIP job releases.
Parameters:rb =
T0 =
W0 =
a =
0.5 pennies/hour
8 hours
0.5 8 = 4 pennies
0 (no variability, best case conditions)
The Penny-Fab-1 (WIP=1)The Penny-Fab-1 (WIP=1)
Time = 0 to 8 hours
Penny Fab-1 Performance
WIP TH CT THCT 1 0.125 8 1 2 0.250 8 2 3 0.375 8 3 4 0.500 8 4 5 6
The Penny Fab-1 (WIP=5)The Penny Fab-1 (WIP=5)
Time = 0 to 10 hours
Penny Fab-1 Performance
WIP TH CT THCT 1 0.125 8 1 2 0.250 8 2 3 0.375 8 3 4 0.500 8 4 5 0.500 10 5 6 0.500 12 6
TH vs. WIP: Best Case
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
TH
rb
W0
1/T0
CT vs. WIP: Best Case
02468
101214161820222426
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
CT
T0
W0
1/rb
Best Case Performance
Best Case Law:
The minimum cycle time (CTbest) for a given WIP level, w, is given byCTbest = T0 , if w ≤ W0
= w / rb, otherwise
The maximum throughput (THbest) for a given WIP level, w is given by,THbest = w/ T0 if w ≤ W0
= rb otherwise
Best Case Performance (cont.)
Example: For Penny Fab-1, rb = 0.5 and T0 = 8, so W0 = 0.5 8 = 4,
which are exactly the curves we plotted.
otherwise.
4 if
,2
,8CTbest
w
w
otherwise.
4 if
,5.0
,8/THbest
ww
Worst Case Observation: The Best Case yields the minimum
cycle time and maximum throughput for each WIP level.
Question: What conditions would cause the maximum cycle time and minimum throughput?
Experiment:Set process times same as Best Case (so rb and T0
unchanged)follow a marked job through systemimagine marked job experiences maximum queueing
Worst Case Penny FabWorst Case Penny Fab
Time = 0 hours
Worst Case Penny FabWorst Case Penny Fab
Time = 8 hours
Worst Case Penny FabWorst Case Penny Fab
Time = 16 hours
Worst Case Penny FabWorst Case Penny Fab
Time = 24 hours
Worst Case Penny FabWorst Case Penny Fab
Time = 32 hours Note:
CT = 32 hours= 4 8 = wT0
TH = 4/32 = 1/8 = 1/T0
TH vs. WIP: Worst Case
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
TH
rb
W0
1/T0
Best Case
Worst Case
CT vs. WIP: Worst Case
048
121620242832
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
CT
T0
W0
Best Case
Worst Case
Worst Case Performance Worst Case Law: The worst case cycle time for a given WIP level, w, is given by,
CTworst = w T0 ( CTbest= w/rb ,=wT0 / W0 )
The worst case throughput for a given WIP level, w, is given by,
THworst = 1 / T0 (Thbest = rb = W0 / T0 )
Randomness? None ! perfectly predictable, but bad!
Practical Worst Case Observation: There is a BIG GAP between the Best
Case and Worst Case performance. Question: Can we find an intermediate case that:
divides “good” and “bad” lines, and is computable?
Experiment: consider a line with a given rb and T0 and variable process time of maximum variability (exp.):single machine stationsbalanced lines, each station has same average timevariability such that all WIP configurations (states) are
equally likely (possible with memory-less exp Process T)
PWC Example – 3 jobs, 4 stations
State Vector State Vector1 (3,0,0,0) 11 (1,0,2,0) 2 (0,3,0,0) 12 (0,1,2,0) 3 (0,0,3,0) 13 (0,0,2,1) 4 (0,0,0,3) 14 (1,0,0,2) 5 (2,1,0,0) 15 (0,1,0,2) 6 (2,0,1,0) 16 (0,0,1,2) 7 (2,0,0,1) 17 (1,1,1,0) 8 (1,2,0,0) 18 (1,1,0,1) 9 (0,2,1,0) 19 (1,0,1,1) 10 (0,2,0,1) 20 (0,1,1,1)
clumped up states
spread out states
Note: average WIP at any station is 15/20 = 0.75, so jobs are spread evenly between stations.
Practical Worst Case
Let w = no. of jobs in system, N = no. stations in line, and t = average process time at all stations:
Average time at a station= time for (this + other) jobs
CT(single) = (1 + (w-1)/N) t
CT(line) = N [1 + (w-1)/N] t = Nt + (w-1)t = T0 + (w-1)/rb
= (W0 + w – 1)/ rb
TH = WIP/CT = [w/(w+W0-1)] rb
From Little’s Law
Practical Worst Case Performance
Practical Worst Case Definition: The practical worst case (PWC) cycle time for a given WIP level, w, is given by,
CTpwc = T0 + (w-1)/ rb
The PWC throughput for a given WIP level, w, is given by,
THpwc = w rb / (W0 + w – 1)
where W0 is the critical WIP.
TH vs. WIP: Practical Worst Case
0
0.1
0.2
0.3
0.4
0.5
0.6
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
TH
rb
W0
1/T0
Best Case
Worst Case
PWCGood (lean)
Bad (fat)
CT vs. WIP: Practical Worst Case
048
121620242832
0 1 2 3 4 5 6 7 8 9 10 11 12
WIP
CT
T0
W0
Best Case
Worst Case PWC
Bad (fat)
Good
(lean)
Penny Fab Two
10 hr
2 hr
5 hr 3 hr
Penny Fab Two
StationNumber
Number ofMachines
ProcessTime
StationRate
1 1 2 hr j/hr
2 2 5 hr j/hr
3 6 10 hr j/hr
4 2 3 hr j/hr
rb = ____________ T0 = ____________ W0 = ____________
0.5
0.4
0.6
0.67
0.4 p/hr 20 hr 8 pennies
Penny Fab Two Simulation (Time=0)
10 hr
2 hr
5 hr 3 hr
2
0
0.1
0.2
0.3
0.4
0.5
0 2 4 6 8 10 12 14 16 18 20 22 24 26
WIP
TH
Penny Fab Two Performance
Worst Case
Penny Fab
PF 2
Best Case
Practical Worst Case
1/T0
rb
W0
Note: processtimes in PF2have var equalto PWC.
But… unlike PWC, it hasunbalancedline and multimachine stations.
Intelligence region
Ignorance region
Penny Fab Two Performance (cont.)
0
10
20
30
40
50
60
70
80
0 2 4 6 8 10 12 14 16 18 20 22 24 26
WIP
CT
Worst Case
Intelligence region
Best Case
Practical Worst
Case
T0
1/rb
W0
Ignorance region
Qualitative categories of Variability Quantitatively we have many discrete (Binomial- tossing
coin/dice, Poisson-Q system) and continuous variable (Expnl. Normal) distributions.
Qualitatively we can categories the variability as follows: Adverse variability Favorable variability Fair variability (Equal rectangular probability- random) Maximum variability (Exponential, memory-less distr.) Minimum var. (Any distr. with low Coeff. Of Var. σ/µ)
21-Feb-12 Prof. S.N. Varma 80
Surprise conclusions1. Variability can be due to Bad control or Randomness or both, but
badly controlled variability , knowingly or unknowingly, is worse than randomness. e.g. in a card game why we want random card? Why we select random person among all equal assumed.
2. Contrary to the balancing of connected and paced assembly line( no waiting Q), throughput of a non paced balanced flow shop with exponential distributed process time can be improved by unbalancing a station of the line. Since all stations are balanced and have TH equal to rb , a station can be unbalanced only by increasing TH of any station, which in turn (1). Reduces T0 , W0 (2). Reduce Q and BN mc
3. Contrary to the belief that throughput can only be increased by improving TH of a BN mc, increasing TH of non BN station will result in less congestion and slightly better results.
21-Feb-12 Prof. S.N. Varma 81
wTH
Prof. S.N. Varma 82
Thanks for Attention.Better info/ knowledge?
Break 2. Time?
21-Feb-12
2-83
Learning ObjectivesExplain Planning-controlling terms; strategic, tactical,
operation; interrelation- without plan what to control?Describe and give examples of time-based strategiesList and briefly discuss the primary ways that
business organizations compete. List reasons for the poor competitiveness of some
companies. Explain why strategy is important for competitivenessContrast strategy and tacticsMIS (ERP) as a strategic Tool for competitiveness
2-84
Learning Objectives
Define the term productivity and explain why it is important to organizations and to countries.
Relation between productivity and standard of livingRelation between Standard of living and happinessProductivity, distribution of benefits and social justiceProductivity and employment shift to servicesList some of the reasons for poor productivity and
some ways of improving it.
Planning and Control ConceptsWhy planning?
Planning is a significant and ongoing activity for mgt and individuals. It provide a framework for taking decisions leading towards the Mission. A Plan is necessary for any activity, though many times it is informal, not on form.
What is a plan:Def. A plan is predetermined course of actions to achieve certain goalsA plan is necessary to measure deviations and control the activities
MISSION
VISION
Goals
Objectives
Strategies
Plans, Budgets
What How
General
Specific
Policies, Rules
Tactics
Planning TerminologyDefinition of terms
Term Definition Example
Mission Broad statement of purpose of organization, assignment, task
Provide high quality product and service
Vision Dream, Aspiration, future state Become fortune 500 Co
Goals Gen. statement of what to achieve
Reduce service-response time without increasing staff
Strategies
Gen. approach to achieve goals
Improve process for handling service-requests
Objective Specific measurable results Reduce service completion time to 2 days
Plan, budgets
Schedule of activities to achieve objectives
Revise service call request
Policy Limit to acceptable behavior Design user friendly interface
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Planning Example
Rita is a high school student. She would like to have a career in business, have a good job, and earn enough income to live comfortably.
Mission: Live a good lifeGoal: Successful career, good income
Strategy: Obtain a college education
Tactics: Select a college and a major
Operations: Register, buy books, take courses, study, graduate, get job
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Planning and Decision Making
Mission
Goals
Organizational Strategies
Functional Goals
Finance Strategies
MarketingStrategies
OperationsStrategies
Tactics Tactics Tactics
Operatingprocedures
Operatingprocedures
Operatingprocedures
Dr. S.N. VARMA
Why Planning is difficult?Why Planning is frequently neglected ? It is a difficult cognitive (hard mental) activity. Avoid cognitive strain. It expose future uncertainties, human tend to avoid uncertainties. It reduce freedom of action (perceived), human avoid restrictions. It needs intensive efforts and concentration so need shut out other
activities It take decision without actual evaluation of envir., assumptions can
be wrong. Due to unreal planning or changes in environment, they are ignored
many times so people become reluctant to planning. It introduce inflexibility in action
Plans have Hierarchy as well network dependency
Strategic plan- time fencing few years (1-5, or more), refer to STRUCTURE
Tactical plan- time few months (1-15), refer to INFRASTRUCTURE/ OPERATION
Operational plan- time fencing freeze to few weeks (1-12), refer to CONTROL
Other plans
Contingency plan (when some distant (Im-) possibility happen)Daily, weekly, monthly,… Five year plans with nesting.
Strategies, policies, SWOTStrategy is from Greek ‘strategos’ (=general)= long-term course of
actionPolicies are general statements/ understandings to guide mgt
decisions; but strategies are to guide resource applications to achieve the goals.
Strategic plans must be supported by tactical and operational planning.
Strategic (general) planning means to analyze current situation, form mission and decide course of actions using resources to achieve goals.
The strategic plan process involve consideration of input (including goal), enterprise profile, top manager orientation, environment & alternative
Opportunity (maxi)
External fact
Threat (mini)
Weakness (mini)--------Internal factors------------------Strength (maxi)
SO strategy (maxi-maxi)
Most successful, utilize strength to take advantage of Opportunities
WO strategy (mini-maxi)e.g. development strategy to overcome weakness and take advantage of opportunity
WT strategy (mini-mini)
e.g. retrenchment, liquidation or joint venture by merging
ST strategy (maxi-mini)
e.g. use of strength to cope with or avoid threats
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Core Competency and Strategy
Distinctive/ Core CompetenciesThe special attributes or abilities that give anorganization a competitive edge
LocationsDistinctive/ core competency, specializationProduct mix and servicesCost, quality, time, flexibilityScale-based strategies
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Banks, ATMsConvenienceLocation
DisneylandNordstroms
Superior customer service
Service
Burger KingSupermarkets
VarietyVolume
Flexibility
Express Mail, Fedex,One-hour photo, UPS
Rapid deliveryOn-time delivery
Time
Sony TVLexus, CadillacPepsi, Kodak, Motorola
High-performance design or high quality Consistent quality
Quality
U.S. first-class postageMotel-6, Red Roof Inns
Low CostCost
Examples of Competitive Strategies
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Strategy FormulationDistinctive/ Core competenciesEnvironmental scanningSWOTOrder qualifiersOrder winnersStrategic decisions must consider globalizationWhat works in one country may not work in anotherOther issues
Political, social, cultural, and economic differences
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Strategy Formulation
Order qualifiers Characteristics that customers perceive as
minimum standards of acceptability to be considered as a potential purchase
Order winnersCharacteristics of an organization’s goods or
services that cause it to be perceived as better than the competition
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External FactorsEconomic conditionsPolitical conditionsLegal environmentTechnologyCompetitionMarkets
Key External and Internal Factors
Internal Factors• Human Resources• Facilities and equipment• Financial resources• Customers• Products and services• Technology• Suppliers
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Strategy must be followed by tactical/ operation plans
Tactical strategy–to take decisions for infrastructure and resources to achieve organization objectives
Operations strategy – The approach, consistent with organization strategy, that is used to guide the operations function.
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Strategic OM DecisionsDecision Area Affects
Product/ service design Costs, quality liability and environment
Capacity Cost structure, flexibility
Process and layout Costs, flexibility, skill level, capacity
Work design Quality of work life, employee safety, productivity
Location Costs, visibility
Quality Ability to meet or exceed customer expectations
Inventory Costs, shortages
Maintenance Costs, equipment reliability, productivity
Scheduling Flexibility, efficiency
Supply chains Costs, quality, agility, shortages, vendor relations
Projects New products, services, or systems
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Quality and Time Strategies
Quality-based strategiesFocuses on maintaining
or improving the quality of an organization’s products or services
Quality at the sourceTime-based strategies
Focuses on reduction of time needed to accomplish tasks
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Competitiveness:
How effectively an organization meets the wants and needs of customers relative to others that offer similar goods or services
Product-Portfolio matrix by BCGCapital Investment and returns are key
issues in strategic plan as well in project plan since it is an important resource; returns vary in rate, risk
Product-Portfolio matrix (Henderson, Boston Consultancy Group, 1970) help in deciding where capital and other resources should be invested STAR PRODUCTSQ-MARK ? PRODUCTS
Release funds by divesting DOGS
Generate funds to investCASH COWS
High
Indus-try growth
LowLow ------------------------Market Share--------------------------- High
Porter Competition-Model,1980Five basic forces affecting competency
and profit potential of industry
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NEW ENTRY Threat
Existing Intra industry Rivalry
Bargaining Power of
SUPPLIERS
SUBSTITUTE Threat
Bargaining Power of BUYERS
Bargaining Power of Suppliers/Buyers
For Suppliers this includes: Input differentiation Supplier concentration Volume Cost relative to total dollars
For Buyers this includes: Buyer concentration Volume Integration
Entry Barriers Economies of scale
Product Differences
Brand Identity
Access to distribution
Cost advantages
Government policy
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Competitive Marketing, Operation Functions
Competitive Marketing Functions:Identifying consumer wants and needsPricingAdvertising and promotion
Competitive Operation Functions:Product and service designCostLocationQualityQuick response
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Why Some Organizations Fail
Too much emphasis on short-term financial performanceFailing to take advantage of strengths and opportunitiesNeglecting operations strategyFailing to recognize competitive threatsToo much emphasis in product and service design and
not enough on improvementNeglecting investments in capital and human resourcesFailing to establish good internal communicationsFailing to consider customer wants and needs….
Push/Pull View of Supply ChainsA Pull process is one driven by customer order and A Push process is
one started by supplier/ mfr in anticipation of customer order
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Procurement,Manufacturing and
Replenishment cyclesCustomer Order
Cycle
CustomerOrder Arrives
PUSH PROCESSES PULL PROCESSES
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Push-Pull view of Manufacturing StrategiesA Pull process is one driven by customer order and A Push process is
one started by supplier/ mfr in anticipation of customer order
A supply/ demand chain can be a pull process (ETO) or a combination of Push and Pull processes depending on the customer order decoupling point
Inventory Location Cust.-order decoupling ptMfg strategy/ environment
Supplier Raw Material WIP Finished Goods^ ^ ^ ^
ETO MTO ATO MTS
ETO = Engineer To Order; MTO = Make To Order
ATO = Assemble To Order (Modular Mfg); MTS = Make To Stock/ Store
Push-Pull Boundary
Customer Order
Push Process Pull process
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ProductivityProductivity: A measure of the effective use of
resources, usually expressed as the ratio of output to input; P = Output / Input (This is a Total measure)Value of this ratio must be more than 1 (synergy)
Partial measures = output/(single input)E.g. Output ; Output ; Output ; Output ;
Labour Raw Material Machine Energy
Multi-factor measures = output/(multiple inputs)E.g. Output ; Output
Labour+Capital+Energy Labour+Machine
Productivity Growth = Current P – Previous P
Previous P
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Units of output per kilowatt-hourDollar value of output per kilowatt-hour
Energy Productivity
Units of output per dollar inputDollar value of output per dollar input
Capital Productivity
Units of output per machine hourValue added / machine cost
Machine Productivity
Units of output per labor hourUnits of output per shiftValue-added per labor hour
Labor Productivity
Partial Productivity Examples
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Factors Affecting Productivity• Capital• Technology• Management• Quality• Standardization• Searching for lost or misplaced items• Scrap rates• Labor turnover, New workers, Layoffs• Safety• Use of Internet, Computer viruses, IT • Design of the workspace• Hygienic Policy and Motivation• Incentive plans that reward productivity
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Improving ProductivityGet management supportDevelop productivity measuresWork study, Method Improvement, Time StandardsMeasure and publicize improvementsEstablish reasonable goalsDetermine critical (bottleneck) operationsDon’t confuse productivity (P>1); efficiency (E< 1)
Standard Of Living and HappinessImproving Productivity generate surplus
and increases material wellbeing- SOL
High SOL does not guarantee Happiness.
Answer is in statistics- a high SOL has high positive correlation with Happiness
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Productivity and EmploymentObjective of productivity improvements is to produce
more with less workerSo we should not wonder or worry for job shift!Presumption- there are infinite work to be done.It is the responsibility of Society and Government to
distribute benefits of productivity with social justice.Leisure time increases with increased productivity (If
your needs are minimum, you can rest without work) Energy can save labor and we feel better- happy.Not only happy but energy also improve longevity.
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