Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.1
7.1
Chapter 7
Layout and flow
Pearson Education Ltd. Rob Judges
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.2
7.2
Supply network design
Layout and Flow
Process technology
People, jobs and
organization
Product/service design
Design
Planning and control
Operations strategy
Improvement
Layout and flow
Layout and flow
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.3
7.3
Service process types
Mass services
Service shops
Manufacturing process types
Continuous processes
Mass processes
Batch processes
Basic layout types
Fixed-position layout
Functional layout
Cell layout
Product layout
The relationship between process and layout types
Jobbing processesProfessional services
Project processes
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.4
7.4
Fixed Position Layout Aviva Stadium
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.5
7.5 Advantages and disadvantages of fixed position layout
Fixed-position layout
Disadvantages
Advantages
Very high product and mix flexibility
Product/customer not moved
High variety of tasks for staff
Very high unit costs
Scheduling space and activities can be difficult
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.6
7.6 Functional layout in a library the path of one customer
Entrance Exit
To journal stack
Study desks
On-line and CD-ROM access room
Loan books in subject orderE
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Store room
Counter staffCopying area
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Current journals
Reserve collection
Reference section
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.7
7.7
Functional layout
Disadvantages
Advantages
High product and mix flexibility
Relatively robust in the case of disruptions
Easy to supervise
Low utilization
Can have very high WIP
Complex flow
Advantages and disadvantages of functional layout
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.8
7.8 Product/Customer Layout - Bottling
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.9
7.9
Product layout
Disadvantages
Advantages
Low unit costs for high volume
Opportunities for specialization of equipment
Can have low mix flexibility
Not very robust in the case of disruptionsWork can be very repetitive
Advantages and disadvantages of product layout
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.10
7.10 Cell Layout - UCD
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.11
7.11
Cell layout
Disadvantages
Advantages
Can give good compromise
Fast throughput
Group work can result in good motivation
Can be costly to rearrange existing layout
Can need more plant
Advantages and disadvantages of cell layout
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.12
7.12 A restaurant complex with all four basic layout types
Fixed-position layout service restaurant
Cell layout buffet
Line layout
cafeteria
Cool roomFreezer Vegetable prep Grill
Preparation
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Functional layout kitchen
Main course buffet
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Service line
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.13
7.13 Detailed design techniques
Fixed position Project management, resource location analysis, experience
Functional layout Complex permutations, efficiency, flow charts and relationship charts
Cell layout Cluster analysis or group technology, product flow analysis
Product layout assembly line balancing techniques, cycle times.
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.14
7.14
1 every 15 minutes
15 15 15 15
1 every 15 minutes
30 30
3030
Long and thin versus short and fat layouts
1 every 15 minutes
60
60
60
60
A 60 minute task with a required cycle time of 15 minutes
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.15
7.15 Long and thin versus short and fat
Advantages of long-thin processescontrolled flowsimple materials handlinglower capital requirement(no duplication)greater efficiencyhigher space utilization
Advantages of short-fat processeshigher mix flexibilityhigher volume flexibility greater robustnessless monotonous
higher ownership
Long and short describes the number of stages
Fat and thin describes the amount of work at each stage
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.16
7.16
Stages in Time Study
BasicTime
ObservedTime
RatingStandard Rating= X
BasicTime
Standard Time =
Allowances+
Standard time for element
Basic time for element
Observed time for element
Rating to adjust for
effortStandard
time for job
Allowances for relaxation
etc.
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.17
7.17
Learning Curve
Time to perform task reduces the more times the task is done.
With manual tasks, humans display learning at an exponential rate
Learning effect more evident for complex, manual and repetitive tasks.
Learning rate is a measure of the progressive reduction in time taken to complete successive tasks
T2 / T1 = T4 / T2 = T8 / T4 = learning rate
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.18
7.18
Example
Learning Rate = 75%, y1 = 1000hrs
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Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.19
7.19
Actual Hrs vs Standard Hrs
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Set
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CP4 01Unit 32 @16,869 Hrs
Last set closed :
Slack, Chambers and Johnston, Operations Management, 6th Edition, Nigel Slack, Stuart Chambers, and Robert Johnston 20107.20
7.20
Learning Data
75% hand assembly/25% machining = 80% learning
50% hand assembly/50% machining = 85% 25% hand assembly/75% machining = 90%
Aerospace 85% Shipbuilding 80-85% Complex machine tools for new models 75-85% Repetitive machining or punch-press operations
90-95% Repetitive welding operations 90%