S ch6
- 2. 6-2
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Process Selection and System Design
Forecasting
Product and
service design
Capacity
planning
Facilities and
Equipment
Layout
Work
design
Process
selection
Technological
change
- 3. 6-3
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Introduction
• Outsourcing, trend, reasons
• Make or Buy?
– Available capacity
– Expertise
– Quality Consideration
– The nature of demand
– Cost
- 4. 6-4
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
• Variety
– How much
• Flexibility
– What degree
• Volume
– Expected output
• The key trade-off
Process Selection
- 5. 6-5
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Process Types
• Projects
• Job Shops
• Batch Processing
• Repetitive/Assembly
• Continuous Processing
- 6. 6-6
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Figure 3.6
Product-Process Matrix for Processes
(1) (2) (3) (4) (5)
One of a kind Low volume, Multiple Few major High volume
products, made low products products, high
to customer standardization moderate higher standardization,
order volume volume commodity
products
Process
Characteristics
(1)
Complex and
highly customized
process, unique
sequence of tasks
(2)
Jumbled flows,
complex work with
many exceptions
(3)
Disconnected line
flows, moderately
complex work
(4)
Connected line,
routine work
(5)
Continuous
flows, highly
repetitive work
LessComplexity,LessDivergence,MoreLineFlows
Less Customization and Higher Volume
Product Design
Continuous
process
Project
process
Line
process
Batch
process
Job
process
- 7. 6-7
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Product-Process Matrix
Flexibility-Quality Dependability-Cost
Continuous
Flow
Assembly
Line
Batch
Job
Shop
Low
Volume
One of a
Kind
Multiple
Products,
Low
Volume
Few
Major
Products,
Higher
Volume
High
Volume,
High
Standard-
ization
Commercial
Printer
Heavy
Equipment
Automobile
Assembly
Sugar
Refinery
Flexibility-
Quality
Dependability
Cost
- 8. 6-8
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
• Automation: Machinery that has
sensing and control devices that
enables it to operate
Automation
- 9. 6-9
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Automation
• Numerically controlled (NC) machines
• Robot
• Computer-aided design and
manufacturing systems (CAD/CAM)
• Flexible manufacturing systems
• Computer-integrated manufacturing
(CIM)
- 10. 6-10
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
• Layout: the configuration of
departments, work centers, and
equipment, with particular emphasis
on movement of work (customers or
materials) through the system
Layout
- 11. 6-11
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
• Requires substantial investments of
money and effort
• Involves long-term commitments
• Has significant impact on cost and
efficiency of short-term operations
Importance of Layout Decisions
- 12. 6-12
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Basic Layout Types
• Product Layouts
• Process Layouts
• Fixed-Position
• Combination Layouts
- 13. 6-13
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Basic Layout Types
• Product Layout
– Layout that uses standardized processing
operations to achieve smooth, rapid, high-
volume flow
– Group equipments according to the sequential
steps of operations of a specific product
• Process Layout
– Layout that can handle varied processing
requirements
– Group equipments according to their functions
- 14. 6-14
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
A Flow Line for Production or Service
Flow Shop or Assembly Line Work Flow
Raw
materials
or customer
Finished
item
Station
2
Station
3
Station
4
Material
and/or
labor
Statio
n
1
Material
and/or
labor
Material
and/or
labor
Material
and/or
labor
- 15. 6-15
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Process Layout
Process Layout - work travels
to dedicated process centers
Milling
Assembly
& Test
Grinding
Drilling Plating
- 16. 6-16
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Functional Layout
Gear
cutting
Mill Drill
Lathes
Grind
Heat
treat
Assembly
111
333
222
444
222
111
444
111 333
1111 2222
222
3333
111
444
111
- 17. 6-17
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Basic Layout Formats
• Group Technology Layout
• Cellular Layout
• Fixed Position Layout
– e.g. Shipbuilding
Part Family W Part Family X
Part Family Y Part Family Z
- 18. 6-18
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Cellular Layouts
• Cellular Manufacturing
– Layout in which machines are grouped into
a cell that can process items that have
similar processing requirements
• Group Technology
– The grouping into part families of items with
similar design or manufacturing
characteristics
- 20. 6-20
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Cellular Manufacturing Layout
-1111 -1111
222222222 - 2222
Assembly
3333333333 - 3333
44444444444444 - 4444
Lathe
Lathe
Mill
Mill
Mill
Mill
Drill
Drill
Drill
Heat
treat
Heat
treat
Heat
treat
Gear
cut
Gear
cut
Grind
Grind
- 21. 6-21
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Design Product Layouts: Line Balancing
Line Balancing is the process of assigning
tasks to workstations in such a way that
the workstations have approximately
equal time requirements.
- 22. 6-22
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Cycle Time
Cycle time is the maximum time
allowed at each workstation to
complete its set of tasks on a unit.
- 23. 6-23
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Determine Maximum Output
Output capacity =
OT
CT
OT operating time per day
D = Desired output rate
CT = cycle time =
OT
D
- 24. 6-24
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Determine the Minimum Number
of Workstations Required: Efficiency
N =
(D)( t)
OT
t = sum of task times
- 25. 6-25
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Precedence Diagram
Precedence diagram: Tool used in line balancing
to display elemental tasks and sequence
requirements
A Simple Precedence
Diagrama b
c d e
0.1 min.
0.7 min.
1.0 min.
0.5 min. 0.2 min.
- 26. 6-26
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Example 1: Assembly Line Balancing
• Arrange tasks shown in the previous
slide into workstations.
– Use a cycle time of 1.0 minute
– Assign tasks in order of the most number of
followers
- 27. 6-27
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Solution to Example 1
Work-
Station
Time
Remaining Eligible
Assign
Task
Station
Idle Time
1 1.0
.9
.2
a
c
none
a
c
- .2
2 1.0
0
b
none
b
- 0
3 1.0
.5
.3
d
e
-
d
e
- .3
.5
- 28. 6-28
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Calculate Percent Idle Time
Percent idle time =
Idle time per cycle
(N)(CT)
- 29. 6-29
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Line Balancing Rules
• Assign tasks in order of most
following tasks.
• Assign tasks in order of greatest
positional weight.
– Positional weight is the sum of each
task’s time and the times of all
following tasks.
Some Heuristic (intuitive) Rules:
- 30. 6-30
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Solution to Example 2
Station 1 Station 2 Station 3 Station 4
a b e
f
d
g h
c
- 31. 6-31
McGraw-Hill/Irwin
Operations Management, Seventh Edition, by William J. Stevenson
Copyright © 2002 by The McGraw-Hill Companies, Inc. All rights reserved.
Process Design and Facility Layout
Parallel Workstations
1 min.2 min.1 min.1 min.
30/hr. 30/hr. 30/hr. 30/hr.
1 min.
1 min.
1 min.1 min.
60/hr.
30/hr. 30/hr.
60/hr.
1 min.
30/hr.
30/hr.
Bottleneck
Parallel Workstations
