Chapter 9 – Layout Strategies

advertisement
Operations
Management
Chapter 9 –
Layout Strategies
PowerPoint presentation to accompany
Heizer/Render
Principles of Operations Management, 7e
Operations Management, 9e
© 2008 Prentice Hall, Inc.
9–1
Outline
; Global Company Profile:
McDonald’s
; The Strategic Importance of
Layout Decisions
; Types of Layout
; Office Layout
© 2008 Prentice Hall, Inc.
9–2
Outline – Continued
; Retail Layout
; Servicescapes
; Warehousing and Storage Layouts
; Cross-Docking
; Random Docking
; Customizing
; Fixed-Position Layout
© 2008 Prentice Hall, Inc.
9–3
Outline – Continued
; Process-Oriented Layout
; Computer Software for ProcessOriented Layouts
; Work Cells
; Requirements of Work Cells
; Staffing and Balancing Work Cells
; The Focused Work Center and the
Focused Factory
© 2008 Prentice Hall, Inc.
9–4
Outline – Continued
; Repetitive and Product-Oriented
Layout
; Assembly-Line Balancing
© 2008 Prentice Hall, Inc.
9–5
Learning Objectives
When you complete this chapter you
should be able to:
1. Discuss important issues in office layout
2. Define the objectives of retail layout
3. Discuss modern warehouse
management and terms such as ASRS,
cross-docking, and random stocking
4. Identify when fixed-position layouts are
appropriate
© 2008 Prentice Hall, Inc.
9–6
Learning Objectives
When you complete this chapter, you
should be able to:
5. Explain how to achieve a good processoriented facility layout
6. Define work cell and the requirements of
a work cell
7. Define product-oriented layout
8. Explain how to balance production flow
in a repetitive or product-oriented facility
© 2008 Prentice Hall, Inc.
9–7
Innovations at McDonald’s
; Indoor seating (1950s)
; Drive-through window (1970s)
; Adding breakfast to the menu
(1980s)
; Adding play areas (late 1980s)
; Redesign of the kitchens (1990s)
; Self-service kiosk (2004)
; Now three separate dining sections
© 2008 Prentice Hall, Inc.
9–8
Innovations at McDonald’s
; Indoor seating (1950s)
; Drive-through window (1970s)
Six out of the
; Adding breakfast to the
menu
seven
are
(1980s)
layout
; Adding play areas (late
1980s)
decisions!
; Redesign of the kitchens (1990s)
; Self-service kiosk (2004)
; Now three separate dining sections
© 2008 Prentice Hall, Inc.
9–9
McDonald’s New Layout
; Seventh major innovation
; Redesigning all 30,000 outlets around
the world
; Three separate dining areas
; Linger zone with comfortable chairs and
Wi-Fi connections
; Grab and go zone with tall counters
; Flexible zone for kids and families
; Facility layout is a source of
competitive advantage
© 2008 Prentice Hall, Inc.
9 – 10
Strategic Importance of
Layout Decisions
The objective of layout strategy
is to develop a cost-effective
layout that will meet a firm’s
competitive needs
© 2008 Prentice Hall, Inc.
9 – 11
Layout Design
Considerations
; Higher utilization of space, equipment,
and people
; Improved flow of information, materials,
or people
; Improved employee morale and safer
working conditions
; Improved customer/client interaction
; Flexibility
© 2008 Prentice Hall, Inc.
9 – 12
Types of Layout
1. Office layout
2. Retail layout
3. Warehouse layout
4. Fixed-position layout
5. Process-oriented layout
6. Work-cell layout
7. Product-oriented layout
© 2008 Prentice Hall, Inc.
9 – 13
Types of Layout
1. Office layout: Positions workers,
their equipment, and spaces/offices
to provide for movement of
information
2. Retail layout: Allocates shelf space
and responds to customer behavior
3. Warehouse layout: Addresses tradeoffs between space and material
handling
© 2008 Prentice Hall, Inc.
9 – 14
Types of Layout
4. Fixed-position layout: Addresses the
layout requirements of large, bulky
projects such as ships and buildings
5. Process-oriented layout: Deals with
low-volume, high-variety production
(also called job shop or intermittent
production)
© 2008 Prentice Hall, Inc.
9 – 15
Types of Layout
6. Work cell layout: Arranges
machinery and equipment to focus
on production of a single product or
group of related products
7. Product-oriented layout: Seeks the
best personnel and machine
utilizations in repetitive or
continuous production
© 2008 Prentice Hall, Inc.
9 – 16
Good Layouts Consider
1. Material handling equipment
2. Capacity and space requirements
3. Environment and aesthetics
4. Flows of information
5. Cost of moving between various
work areas
© 2008 Prentice Hall, Inc.
9 – 17
Layout Strategies
Office
Retail
Warehouse
(storage)
Examples
Allstate Insurance
Microsoft Corp.
Locate workers
requiring frequent
contact close to
one another
Kroger’s
Supermarket
Federal-Mogul’s
warehouse
Walgreen’s
The Gap’s
distribution center
Bloomingdale’s
Problems/Issues
Expose customer
to high-margin
items
Balance low-cost
storage with lowcost material
handling
Table 9.1
© 2008 Prentice Hall, Inc.
9 – 18
Layout Strategies
Project
(fixed position)
Job Shop
(process oriented)
Examples
Ingall Ship Building
Corp.
Trump Plaza
Arnold Palmer Hospital
Hard Rock Café
Olive Garden
Pittsburgh Airport
Problems/Issues
Manage varied material
Move material to the
flow for each product
limited storage areas
around the site
Table 9.1
© 2008 Prentice Hall, Inc.
9 – 19
Layout Strategies
Work Cells
(product families)
Repetitive/ Continuous
(product oriented)
Examples
Hallmark Cards
Wheeled Coach
Standard Aero
Problems/Issues
Identify a product
family, build teams,
cross train team
members
Sony’s TV assembly
line
Toyota Scion
Equalize the task time
at each workstation
Table 9.1
© 2008 Prentice Hall, Inc.
9 – 20
Office Layout
; Grouping of workers, their equipment,
and spaces to provide comfort,
safety, and movement of information
; Movement of
information is main
distinction
; Typically in state of
flux due to frequent
technological
changes
© 2008 Prentice Hall, Inc.
9 – 21
Relationship Chart
Figure 9.1
© 2008 Prentice Hall, Inc.
9 – 22
Supermarket Retail Layout
; Objective is to maximize
profitability per square foot of
floor space
; Sales and profitability vary
directly with customer exposure
© 2008 Prentice Hall, Inc.
9 – 23
Five Helpful Ideas for
Supermarket Layout
1. Locate high-draw items around the
periphery of the store
2. Use prominent locations for high-impulse
and high-margin items
3. Distribute power items to both sides of
an aisle and disperse them to increase
viewing of other items
4. Use end-aisle locations
5. Convey mission of store through careful
positioning of lead-off department
© 2008 Prentice Hall, Inc.
9 – 24
Store Layout
Figure 9.2
© 2008 Prentice Hall, Inc.
9 – 25
Retail Slotting
; Manufacturers pay fees to retailers
to get the retailers to display (slot)
their product
; Contributing factors
; Limited shelf space
; An increasing number of new
products
; Better information about sales
through POS data collection
; Closer control of inventory
© 2008 Prentice Hall, Inc.
9 – 26
Retail Store Shelf Space
Planogram
Shampoo
Shampoo
Shampoo
Shampoo
Conditioner
Shampoo
Shampoo
Shampoo
Conditioner
Conditioner
; Often supplied
by manufacturer
Shampoo
; Generated from
store’s scanner
data on sales
Shampoo
; Computerized
tool for shelfspace
management
5 facings
2 ft.
© 2008 Prentice Hall, Inc.
9 – 27
Servicescapes
; Ambient conditions - background
characteristics such as lighting, sound,
smell, and temperature
; Spatial layout and functionality - which
involve customer
circulation path planning,
aisle characteristics, and
product grouping
; Signs, symbols, and
artifacts - characteristics
of building design that
carry social significance
© 2008 Prentice Hall, Inc.
9 – 28
Warehousing and Storage
Layouts
; Objective is to optimize trade-offs
between handling costs and costs
associated with warehouse space
; Maximize the total “cube” of the
warehouse – utilize its full volume
while maintaining low material
handling costs
© 2008 Prentice Hall, Inc.
9 – 29
Warehousing and Storage
Layouts
Material Handling Costs
; All costs associated with the transaction
; Incoming transport
; Storage
; Finding and moving material
; Outgoing transport
; Equipment, people, material, supervision,
insurance, depreciation
; Minimize damage and spoilage
© 2008 Prentice Hall, Inc.
9 – 30
Warehousing and Storage
Layouts
; Warehouse density tends to vary
inversely with the number of different
items stored
; Automated Storage and
Retrieval Systems (ASRSs)
can significantly improve
warehouse productivity by
an estimated 500%
; Dock location is a key
design element
© 2008 Prentice Hall, Inc.
9 – 31
Cross-Docking
; Materials are moved directly from
receiving to shipping and are not
placed in storage
in the warehouse
; Requires tight
scheduling and
accurate shipments,
bar code or RFID
identification used for
advanced shipment
notification as materials
are unloaded
© 2008 Prentice Hall, Inc.
9 – 32
Random Stocking
; Typically requires automatic identification
systems (AISs) and effective information
systems
; Random assignment of stocking locations
allows more efficient use of space
; Key tasks
1. Maintain list of open locations
2. Maintain accurate records
3. Sequence items to minimize travel, pick time
4. Combine picking orders
5. Assign classes of items to particular areas
© 2008 Prentice Hall, Inc.
9 – 33
Customizing
; Value-added activities performed at
the warehouse
; Enable low cost and rapid response
strategies
; Assembly of components
; Loading software
; Repairs
; Customized labeling and packaging
© 2008 Prentice Hall, Inc.
9 – 34
Warehouse Layout
Traditional Layout
Customization
Storage racks
Conveyor
Staging
Office
Shipping and receiving docks
© 2008 Prentice Hall, Inc.
9 – 35
Warehouse Layout
Cross-Docking Layout
Office
Shipping and receiving docks
Shipping and receiving docks
© 2008 Prentice Hall, Inc.
9 – 36
Fixed-Position Layout
; Product remains in one place
; Workers and equipment come to site
; Complicating factors
; Limited space at site
; Different materials
required at different
stages of the project
; Volume of materials
needed is dynamic
© 2008 Prentice Hall, Inc.
9 – 37
Alternative Strategy
; As much of the project as possible
is completed off-site in a productoriented facility
; This can
significantly
improve efficiency
but is only
possible when
multiple similar
units need to be created
© 2008 Prentice Hall, Inc.
9 – 38
Process-Oriented Layout
; Like machines and equipment are
grouped together
; Flexible and capable of handling a
wide variety of products or
services
; Scheduling can be difficult and
setup, material handling, and labor
costs can be high
© 2008 Prentice Hall, Inc.
9 – 39
Process-Oriented Layout
ER
triage
room
Patient A - broken leg
Emergency room admissions
Patient B - erratic heart
pacemaker
Surgery
Laboratories
Radiology
ER Beds
Pharmacy
Billing/exit
Figure 9.3
© 2008 Prentice Hall, Inc.
9 – 40
Layout at Arnold Palmer Hospital
Pie-shaped
rooms
Central break
and medical
supply rooms
Local linen
supply
© 2008 Prentice Hall, Inc.
Central nurses
station
Local
nursing pod
9 – 41
Process-Oriented Layout
; Arrange work centers so as to
minimize the costs of material
handling
; Basic cost elements are
; Number of loads (or people) moving
between centers
; Distance loads (or people) move
between centers
© 2008 Prentice Hall, Inc.
9 – 42
Process-Oriented Layout
n
n
Minimize cost = ∑ ∑ Xij Cij
i=1 j=1
where
© 2008 Prentice Hall, Inc.
n = total number of work centers or
departments
i, j = individual departments
Xij = number of loads moved from
department i to department j
Cij = cost to move a load between
department i and department j
9 – 43
Process Layout Example
Arrange six departments in a factory to
minimize the material handling costs.
Each department is 20 x 20 feet and the
building is 60 feet long and 40 feet wide.
1. Construct a “from-to matrix”
2. Determine the space requirements
3. Develop an initial schematic diagram
4. Determine the cost of this layout
5. Try to improve the layout
6. Prepare a detailed plan
© 2008 Prentice Hall, Inc.
9 – 44
Process Layout Example
Number of loads per week
Department Assembly Painting
(1)
(2)
Assembly (1)
Painting (2)
Machine Shop (3)
Receiving (4)
Shipping (5)
50
Machine Receiving
Shop (3)
(4)
Shipping
(5)
Testing
(6)
100
0
0
20
30
50
10
0
20
0
100
50
0
0
Testing (6)
Figure 9.4
© 2008 Prentice Hall, Inc.
9 – 45
Process Layout Example
Area 1
Area 2
Area 3
Assembly
Department
(1)
Painting
Department
(2)
Machine Shop
Department
(3)
40’
Figure 9.5
© 2008 Prentice Hall, Inc.
Receiving
Department
(4)
Shipping
Department
(5)
Testing
Department
(6)
Area 4
Area 5
60’
Area 6
9 – 46
Process Layout Example
Interdepartmental Flow Graph
100
1
50
20
50
4
50
2
10
30
3
20
100
5
6
Figure 9.6
© 2008 Prentice Hall, Inc.
9 – 47
Process Layout Example
n
n
Cost = ∑ ∑ Xij Cij
i=1 j=1
Cost =
$50
+ $200 +
$40
(1 and 2)
(1 and 3)
(1 and 6)
+
$30
+
$50
+
$10
(2 and 3)
(2 and 4)
(2 and 5)
+
$40
+ $100 +
$50
(3 and 4)
(3 and 6)
(4 and 5)
= $570
© 2008 Prentice Hall, Inc.
9 – 48
Process Layout Example
Revised Interdepartmental Flow Graph
30
50
2
1
10
20
50
4
50
100
3
100
50
5
6
Figure 9.7
© 2008 Prentice Hall, Inc.
9 – 49
Process Layout Example
n
n
Cost = ∑ ∑ Xij Cij
i=1 j=1
Cost =
$50
+ $100 +
$20
(1 and 2)
(1 and 3)
(1 and 6)
+
$60
+
$50
+
$10
(2 and 3)
(2 and 4)
(2 and 5)
+
$40
+ $100 +
$50
(3 and 4)
(3 and 6)
(4 and 5)
= $480
© 2008 Prentice Hall, Inc.
9 – 50
Process Layout Example
Area 1
Area 2
Area 3
Painting
Department
(2)
Assembly
Department
(1)
Machine Shop
Department
(3)
40’
Figure 9.8
© 2008 Prentice Hall, Inc.
Receiving
Department
(4)
Shipping
Department
(5)
Testing
Department
(6)
Area 4
Area 5
60’
Area 6
9 – 51
Computer Software
; Graphical approach only works for
small problems
; Computer programs are available to
solve bigger problems
; CRAFT
; ALDEP
; CORELAP
; Factory Flow
© 2008 Prentice Hall, Inc.
9 – 52
CRAFT Example
1
PATTERN
2
3
4
5
6
1
D
D
D
D
B
B
B
2
D
D
D
D
B
B
D
D
3
D
D
D
E
E
E
D
D
D
4
C
C
D
E
E
F
F
F
F
D
5
A
A
A
A
A
F
E
E
E
D
6
A
A
A
F
F
F
1
PATTERN
2
3
4
5
6
1
A
A
A
A
B
B
2
A
A
A
A
B
3
D
D
D
D
4
C
C
D
5
F
F
6
E
E
TOTAL COST
20,100
EST. COST REDUCTION
ITERATION
0
(a)
© 2008 Prentice Hall, Inc.
.00
TOTAL COST
14,390
EST. COST REDUCTION
ITERATION
3
(b)
70.
Figure 9.9
9 – 53
Computer Software
; Three dimensional visualization
software allows managers to view
possible layouts and assess process,
material
handling,
efficiency,
and safety
issues
© 2008 Prentice Hall, Inc.
9 – 54
Work Cells
; Reorganizes people and machines
into groups to focus on single
products or product groups
; Group technology identifies
products that have similar
characteristics for particular cells
; Volume must justify cells
; Cells can be reconfigured as
designs or volume changes
© 2008 Prentice Hall, Inc.
9 – 55
Advantages of Work Cells
1. Reduced work-in-process inventory
2. Less floor space required
3. Reduced raw material and finished
goods inventory
4. Reduced direct labor
5. Heightened sense of employee
participation
6. Increased use of equipment and
machinery
7. Reduced investment in machinery
and equipment
© 2008 Prentice Hall, Inc.
9 – 56
Improving Layouts Using
Work Cells
Current layout - workers
in small closed areas.
Cannot increase output
without a third worker and
third set of equipment.
Improved layout - cross-trained
workers can assist each other.
May be able to add a third worker
as additional output is needed.
Figure 9.10 (a)
© 2008 Prentice Hall, Inc.
9 – 57
Improving Layouts Using
Work Cells
Current layout - straight
lines make it hard to balance
tasks because work may not
be divided evenly
Figure 9.10 (b)
© 2008 Prentice Hall, Inc.
Improved layout - in U
shape, workers have better
access. Four cross-trained
workers were reduced.
U-shaped line may reduce employee movement
and space requirements while enhancing
communication, reducing the number of
workers, and facilitating inspection
9 – 58
Requirements of Work Cells
1. Identification of families of products
2. A high level of training, flexibility
and empowerment of employees
3. Being self-contained, with its own
equipment and resources
4. Test (poka-yoke) at each station in
the cell
© 2008 Prentice Hall, Inc.
9 – 59
Staffing and Balancing
Work Cells
Determine the takt time
Total work time available
Takt time =
Units required
Determine the number
of operators required
Total operation time required
Workers required =
Takt time
© 2008 Prentice Hall, Inc.
9 – 60
Staffing Work Cells
Example
Standard time required
600 Mirrors per day required
Mirror production scheduled for 8 hours per day
From a work balance chart 60
total operation time 50
= 140 seconds
40
30
20
10
0
Assemble Paint
Test
Label Pack for
shipment
Operations
© 2008 Prentice Hall, Inc.
9 – 61
Staffing Work Cells
Example
600 Mirrors per day required
Mirror production scheduled for 8 hours per day
From a work balance chart
total operation time
= 140 seconds
Takt time = (8 hrs x 60 mins) / 600 units
= .8 mins = 48 seconds
Total operation time required
Workers required =
Takt time
= 140 / 48 = 2.91
© 2008 Prentice Hall, Inc.
9 – 62
Work Balance Charts
; Used for evaluating operation
times in work cells
; Can help identify bottleneck
operations
; Flexible, cross-trained employees
can help address labor bottlenecks
; Machine bottlenecks may require
other approaches
© 2008 Prentice Hall, Inc.
9 – 63
Focused Work Center and
Focused Factory
; Focused Work Center
; Identify a large family of similar products
that have a large and stable demand
; Moves production from a general-purpose,
process-oriented facility to a large work cell
; Focused Factory
; A focused work cell in a separate facility
; May be focused by product line, layout,
quality, new product introduction, flexibility,
or other requirements
© 2008 Prentice Hall, Inc.
9 – 64
Focused Work Center and
Focused Factory
Work Cell
A work cell is a
temporary productoriented arrangement
of machines and
personnel in what is
ordinarily a processoriented facility.
Focused Work Center
A focused work center is A focused factory is a
a permanent productpermanent facility to
oriented arrangement
produce a product or
of machines and
component in a
personnel in what is
product-oriented
ordinarily a processfacility. Many focused
oriented facility.
factories currently
being built were
originally part of a
process-oriented
facility.
Example: A job shop
Example: Pipe bracket
with machinery and
manufacturing at a
personnel rearranged
shipyard.
to produce 300 unique
control panels.
© 2008 Prentice Hall, Inc.
Focused Factory
Example: A plant to
produce window
mechanism for
automobiles.
Table 9.2
9 – 65
Repetitive and ProductOriented Layout
Organized around products or families of
similar high-volume, low-variety products
1. Volume is adequate for high equipment
utilization
2. Product demand is stable enough to justify high
investment in specialized equipment
3. Product is standardized or approaching a phase
of life cycle that justifies investment
4. Supplies of raw materials and components are
adequate and of uniform quality
© 2008 Prentice Hall, Inc.
9 – 66
Product-Oriented Layouts
; Fabrication line
; Builds components on a series of machines
; Machine-paced
; Require mechanical or engineering changes
to balance
; Assembly line
; Puts fabricated parts together at a series of
workstations
; Paced by work tasks
; Balanced by moving tasks
Both types of lines must be balanced so that the
time to perform the work at each station is the same
© 2008 Prentice Hall, Inc.
9 – 67
Product-Oriented Layouts
Advantages
1.
2.
3.
4.
5.
Low variable cost per unit
Low material handling costs
Reduced work-in-process inventories
Easier training and supervision
Rapid throughput
Disadvantages
1. High volume is required
2. Work stoppage at any point ties up the
whole operation
3. Lack of flexibility in product or production
rates
© 2008 Prentice Hall, Inc.
9 – 68
McDonald’s Assembly Line
Figure 9.12
© 2008 Prentice Hall, Inc.
9 – 69
Disassembly Lines
• Disassembly is being considered in
new product designs
• “Green” issues and recycling
standards are important consideration
• Automotive
disassembly is
the 16th largest
industry in
the US
© 2008 Prentice Hall, Inc.
9 – 70
Assembly-Line Balancing
; Objective is to minimize the imbalance
between machines or personnel while
meeting required output
; Starts with the precedence
relationships
1. Determine cycle time
2. Calculate theoretical
minimum number of
workstations
3. Balance the line by
assigning specific
tasks to workstations
© 2008 Prentice Hall, Inc.
9 – 71
Wing Component Example
Performance Task Must Follow
Time
Task Listed
Task
(minutes)
Below
A
10
—
B
11
A
C
5
B
D
4
B
E
12
A
F
3
C, D
G
7
F
H
11
E
I
3
G, H
Total time 66
© 2008 Prentice Hall, Inc.
This means that
tasks B and E
cannot be done
until task A has
been completed
9 – 72
Wing Component Example
Performance Task Must Follow
Time
Task Listed
Task
(minutes)
Below
A
10
—
B
11
A
C
5
B
D
4
B
E
12
A
F
3
C, D
G
7
F
10
H
11
E
A
I
3
G, H
Total time 66
5
11
B
12
E
C
4
D
3
7
F
G
3
11
I
H
Figure 9.13
© 2008 Prentice Hall, Inc.
9 – 73
Wing Component Example
480 available
Performance Task Must Follow
mins per day
Time
Task Listed
40 units required
Task
(minutes)
Below
A
10
—
B
11
A
Production time
C
5
B
available per day
Cycle
D
4
B time = Units required per day
E
12
A
= 480 / 40
5
F
3
C, D
= 12 minutes per unit
C
G
7
F
10
11
3
7
n
H
11
E
for taskFi
A ∑ Time
B
G
Minimum
I
3
G, H
4
i=1
3
number of =
Cycle Dtime
Total time 66
workstations
I
12
11
= 66 / 12
E
H
= 5.5 or 6 stations
Figure 9.13
© 2008 Prentice Hall, Inc.
9 – 74
Heuristics
WingLine-Balancing
Component
Example
1. Longest task time
Choose the available
480 task
available
Performance Task Must
Follow
with the longest task time
mins per day
Time
Task Listed
40 task
units required
Task2. Most
(minutes)
Choose the available
following tasksBelow
number
of= 12 mins
A
10
—with the largestCycle
time
B
11
Afollowing tasksMinimum
= 5.5 or 6
C 3. Ranked5 positional
BChoose the available
workstations
task for
D
Bwhich the sum of following
weight4
E
12
Atask times is the longest
5
F
3
C, D
the available
C task
G 4. Shortest
7 task time
FChoose
10 shortest
11
3
7
with the
task time
H
11
E
A
B
G
F
I 5. Least number
3
G,
H
4
of
Choose the available
task
3
with the least number
of
Totalfollowing
time 66 tasks
D
I
12
11
following tasks
E
H
Table 9.4
Figure 9.13
© 2008 Prentice Hall, Inc.
9 – 75
Wing Component Example
480 available
Performance Task Must Follow
mins per day
Time
Task Listed
40 units required
Task
(minutes)
Below
A
10
—
Cycle time = 12 mins
B
11
A
Minimum
Station
5
= 5.5 or 6
C
52
B
workstations
C B
D
4
11
3
7
E 10
12
A
B
F
G
F A
3
C, D
4
3
G
7
F
D E Station 3
H
11
I
I
3
G, H
12
11
Station 6
Stationtime 66
Total
E
H
1
Station
4
© 2008 Prentice Hall, Inc.
Station
5
Figure 9.14
9 – 76
Wing Component Example
480 available
Performance Task Must Follow
mins per day
Time
Task Listed
40 units required
Task
(minutes)
Below
A
10
—
Cycle time = 12 mins
B
11
A
Minimum
= 5.5 or 6
C
5
B
workstations
D
4
B
E
12
A
F
3
C, D
∑ Task times
G
7
F
Efficiency =
(Actual number ofEworkstations) x (Largest cycle time)
H
11
I
3
G, H
= 66 minutes / (6 stations) x (12 minutes)
Total time 66
= 91.7%
© 2008 Prentice Hall, Inc.
9 – 77
Download