plant layout
TRANSCRIPT
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Plant Layout
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Layout PlanningManufacturing & Services
• Deals with the physical arrangement of various resources that are available in the system with an objective to improve the performance of the operating system thereby providing better customer service.
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Inefficient operations
For Example:
High CostBottlenecks
Changes in the designof products or services
The introduction of newproducts or services
Accidents
Safety hazards
The Need for Layout Decisions
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Changes inenvironmentalor other legalrequirements
Changes in volume ofoutput or mix of
products
Changes in methodsand equipment
Morale problems
The Need for Layout Design (Cont’d)
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Implications of layout Planning
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• Relationship between volume-variety –flow provides crucial input for layout planning.
• As the flow becomes more cumbersome, the type of layout may significantly influence the ability of operations manager to effectively plan.
• Table8.1 of Mahadevan
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Types of Layout
• Process
• Product
• Group Technology
• Fixed Position
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Process Layout - work travels to dedicated process centers
Milling
Assembly& Test Grinding
Drilling Plating
Process Layout
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Gearcutting
Mill Drill
Lathes
Grind
Heattreat
Assembly
111
333
222
444
222111444
111 3331111 2222
222
3333
111
444111
333333333
44444
3333
3322
222
Functional Layout
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-1111 -1111
2222 - 2222
Ass
emb
ly
3333 - 3333
4444 - 4444
Lathe
Lathe
Mill
Mill
Mill
Mill
Drill
Drill
Drill
Heat treat
Heat treat
Heat treat
Gear cut
Gear cut
Grind
Grind
Cellular Manufacturing Layout
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Process Layout
• Arrangement of resources on the basis of the process characteristics of the resources available.
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Process LayoutExamples
• Car servicing
• Hospital-Patient requiring various tests
• Volume low & variety is more
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Product Layout
• The resources are placed to follow exactly the visitation sequence dictated by the product.
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Product layout
• The technique employed for product layout is known as line balancing
• The resources required to achieve desired /targeted production rate.
• Cycle time can be considered as a reciprocal of production rate.
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Product layout
• Plant & machinery layout is designed to cater to continuous flow of Materials.
• Use of mechanisation and automation can be planned.
• Automobile Industry
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Advantages
• Process• Sharing of
specialised and costly equipment
• More flexibility• Less vulnerable to
breakdowns
• Product • Standardised product
and process routing • Operational control is
simpler• High output rate is
possible
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Disadvantages
• Process• Large inventory build
up• Excess material
handling
• Product • Less flexibility due to
dedication of resources
• Possibility of duplicating equipments leading to higher costs.
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Group Technology Layout
• This is philosophy that seeks to exploit the commonality in manufacturing and uses this as a basis for grouping components and resources. This is also known as cellular manufacturing.
• Pioneered by Russians• Mid volume & mid variety scenario• 70% of mfg. industry may fall under this
category)
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Advantages of Cellular Layout
• PPC becomes simpler
• Material handling becomes easier
• Traceability improves
• Employees are able to relate better.
• Helps in implementing SGA, Kaizen an JIT
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Cellular Layout- Examples
• Reliance industries- HDPE & LDPE
• Titan Industry
• ABB( Industrial fans & blowers)
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Fixed Position Layout
• The material remains in a fixed position , but the machinery, tool workmen etc are brought to the material
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Fixed Position Layout
• Employed in large project type organisation
• Example• ISRO• Helicopter• Nuclear engg. Division of BHEL
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• One worker and multiple machine layout
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Layout Design for Services
• Critical factors
• Degree of customer contact
• Line visibility
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Performance Measures
• The most fundamental measure for layout design is the distance travelled by customer order in the system.
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Performance Measures
1. Distance travelled by job in the SF
2. Space utilisation index
3. Matl. Handling costs
4. Lead time of the process
5. Ease of prodn. Control
6. No. of ownership changes
• Kg Mts.
• Rs./month• Hrs per avg. product• Size of progress
chasing staff• No. of times job
changes hand.
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• Automation: Machinery that has sensing and control devices that enables it to operate– Fixed automation– Programmable automation
Automation
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• Computer-aided design and manufacturing systems (CAD/CAM)
• Numerically controlled (NC) machines
• Robot
• Manufacturing cell
• Flexible manufacturing systems(FMS)
• Computer-integrated manufacturing (CIM)
Automation
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Dimension Functional CellularNumber of moves between departments
many few
Travel distances longer shorter
Travel paths variable fixed
Job waiting times greater shorter
Throughput time higher lower
Amount of work in process
higher lower
Supervision difficulty higher lower
Scheduling complexity higher lower
Equipment utilization lower higher
Table 6.3Functional vs. Cellular Layouts
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• Warehouse and storage layouts
• Retail layouts
• Office layouts
Other Service Layouts
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Line Balancing is the process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements.
Design Product Layouts: Line Balancing
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Cycle time is the maximum time allowed at each workstation tocomplete its set of tasks on a unit.
Cycle Time
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O utput capac ity = O T
C T
O T operating tim e per day
D = D es ired output ra te
C T = cyc le tim e = O T
D
O utput capac ity = O T
C T
O T operating tim e per day
D = D es ired output ra te
C T = cyc le tim e = O T
D
Determine Maximum Output
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N = (D)( t)
OT
t = sum of task times
Determine the Minimum Number of Workstations Required