mangement
Layout Strategies
Chapter 9
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Learning Objectives
When you complete this chapter you should be able to:
Define the objectives of layout
Discuss important issues in layout strategies
Discuss modern warehouse management and terms such as cross-docking
Identify when each type of layout is appropriate
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
2
When you complete this chapter you should be able to:
Learning Objectives
Explain how to achieve a good process-oriented facility layout
Define work cell and the requirements of a work cell
Explain how to balance production flow in a repetitive or product-oriented facility
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
3
Strategic Importance of Layout Decisions
The objective of layout strategy is to develop an effective and efficient layout that will meet the firm’s competitive requirements
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
4
What is Layout?
Layout refers to the configuration of departments, work centers and equipment with emphasis on movement of work (customers or materials) through the system.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
5
Layout Decisions
Layout decisions:
Requires substantial investments of money and effort
Involve long term commitment, which makes mistakes difficult to overcome
They have a significant impact on the cost and efficiency of operations.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
6
7
Inefficient operations
For Example:
High Cost
Bottlenecks
Changes in the design
of products or services
The introduction of new products or services
Accidents
Safety hazards
The Need for Layout Decisions
FYI
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
7
8
Changes in
environmental
or other legal
requirements
Changes in volume of
output or mix of
products
Changes in methods
and equipment
Morale problems
The Need for Layout Design (Cont’d)
FYI
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
8
Layout Design Consideration
Layout design must consider how to achieve the following:
Improved flow of information, materials, or people
Improved employee morale and safer working conditions
Improved customer interaction
Flexibility
Minimal material handling costs
Efficient use of space
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
9
Most common reason for redesign of layout
Inefficient operation (e.g., high cost, bottleneck)
Safety hazards
Change in the design of product or service
Changes in the volume of output
Morale problem (e.g., lack of face to face contact)
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
10
The 7 Types of Layouts
Manufacturing layouts:
Process-oriented layout (job shop)
Product-oriented layout (repetitive/ product)
Work-cell layout (mass customization)
Other layouts:
Office layout
Retail layout
Fixed-position layout
Warehouse layout
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
11
Types of Layout
Office layout: Positions workers and their equipment for flow of information
Retail layout: Positions products to maximize product exposure & net profit per unit of space (e.g. supermarket, grocery store, department store).
Warehouse layout: Positions products according to trade-offs between material handling & space https://www.youtube.com/watch?v=AEKMgCmLcRc
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
12
Types of Layout
Fixed-position layout: Item being worked on remains stationary, and workers, materials and equipment are moved as needed (e.g. Shipbuilding, house building, power plant etc.) In fixed position layout, equipment and workers move to the project.
Process-oriented layout: Positions departments or work centers low-volume, high-variety production environments to minimize handling and movement costs (e.g. hospital & bank)
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
13
Types of Layout
Work cell layout: Layout in which machines are grouped into a cell that can process items that have similar processing requirements.
Product-oriented layout: Deals with setting up assembly lines in high-volume, low-variety production environments to balance work among workstations in repetitive or continuous production
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
14
Layout Strategies
| Type of Layout | Objectives |
| Office | Locate workers requiring frequent contact close to one another |
| Retail | Expose customer to high-margin items |
| Warehouse | Balance low-cost storage with low-cost material handling |
| Fixed position | Move material/equipment to the limited storage areas around the site |
| Process oriented (Job Shop) | Manage varied material flow for each product/service |
| Work Cell | Improve process flow for better speed & quality, and eliminate waste to reduce cost. |
| Product oriented (Repetitive/Continuous ) | Equalize the task time at each workstation |
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
15
Office Layout
Grouping of workers, their equipment, and spaces to provide comfort, safety, and movement of information
Movement of information is main distinction
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
16
Relationship Chart
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Retail Layout
The main goal of retail layout is:
Minimizing material handling cost.
Minimizing customer confusion regarding location of items.
Minimizing storage costs.
Minimizing space required.
Maximizing profitability per square foot of floor space.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
18
Retail Layout
We expect Walmart ‘s fiscal 2019 store SALES per square foot of $468
Source: Forbes
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
19
Five helpful ideas for supermarket layout
Locate high-draw items around the outside of the store
Use prominent locations for high-impulse and high-margin items
Distribute power items to both sides of an aisle and disperse them to increase viewing of other items
Use end-aisle locations
Convey mission of store through careful positioning of lead-off department
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Slotting fees
Manufacturers pay slotting 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
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
21
Slotting fees
How ethical are slotting fees?
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
22
Slotting fees
Slotting fees put small company with a new product at a disadvantage because small companies with limited resources may be squeezed out of the marketplace.
Slotting fees may also mean that customers may no longer be able to find the special local brand.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
23
Servicescapes
Servicescape: the physical surroundings in which a service takes place, and how they affect customers and employees.
To provide a good service layout, a firm considers 3 elements:
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
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Warehouse and Storage Layouts
The design of storage facilities present a different set of factors than the design of factory layouts.
Frequency of order is an important consideration:
Items that are ordered frequently should be placed near the entrance of the facility
Items that are ordered infrequently should be placed in the rear of the facility.
The goal is to minimize picking time and transportation
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
25
Warehouse and Storage Layouts
Objective is to find the optimum 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
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
26
Warehousing and Storage Layouts
Material handling does not add value to the product; it’s just waste.
Objective: Minimize material handling as well as combining with other operations when possible, eliminating unnecessary and costly movements.
All costs associated with the transaction. This consist of:
Incoming transport
Storage
Finding and moving material
Outgoing transport
Equipment, people, material, supervision, insurance, depreciation
Effective warehouse layout will minimize the damage and spoilage of material within warehouse
Material Handling Costs
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
27
Warehousing and Storage Layouts
Without investing in optimisation of your warehouse design and layout, you may well soon find yourself in a suboptimal situation with:
High warehousing and handling costs
Less efficient processes
Subpar customer service
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
28
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
Dock location is a key design element
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
29
Warehousing and Storage Layouts
The following areas must be perfectly defined when designing a layout:
Loading and unloading areas
Reception area
Storage area
Picking area
Dispatch area
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
30
Cross-Docking
Cross-Docking: Materials are moved directly from receiving to shipping and are not placed in storage in the warehouse.
Advantage of cross docking:
Reduces material handling.
Reduces need to store products in warehouse.
No need for large warehouse areas
Reduced labor costs (no packaging and storing).
Reduced time to reach customer.
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
31
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
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
32
Process-Oriented Layout
Workstations are physically organized according to the operations they perform
eg. All drilling machines located in the drilling department.
eg. All accountants located in the accounting department
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.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
33
Process-Oriented Layout
Example: The hospital groups together functions such as intensive care, surgery, emergency medicine, and radiology as separate departments.
This arrangement allows one patient entering through the emergency room to be seen in radiology, possibly surgery, and then intensive care, and another to be admitted directly for elective surgery and then to intensive care.
The variability among patients makes such flexibility necessary.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
34
Process-Oriented Layout
Process layouts are found primarily in job shops, or firms that produce customized, low-volume products that may require different processing requirements and sequences of operations.
Process layouts are facility configurations in which operations of a similar nature or function are grouped together.
Their purpose is to process goods or provide services that involve a variety of processing requirements.
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
35
Process-Oriented Layout
All machines performing a particular process are grouped together in a processing department
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
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
36
Surgery
Radiology
ER triage room
ER Beds
Pharmacy
Emergency room admissions
Billing/exit
Laboratories
Process-Oriented Layout
Patient A - broken leg
Patient B - erratic heart pacemaker
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
37
Process-Oriented Layout
where 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 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
38
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. The cost of moving one load:
Assume:
The movement between adjacent departments is estimated to be $1
The movement between nonadjacent departments is estimated to be $2
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
39
Process Layout Example
Construct a “from-to matrix”
Determine the space requirements
Develop an initial schematic diagram
Determine the cost of this layout
Try to improve the layout
Prepare a detailed plan
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
40
Department Assembly Painting Machine Receiving Shipping Testing
(1) (2) Shop (3) (4) (5) (6)
Assembly (1)
Painting (2)
Machine Shop (3)
Receiving (4)
Shipping (5)
Testing (6)
Number of loads per week
50 100 0 0 20
30 50 10 0
20 0 100
50 0
0
Process Layout Example from-to-matrix
Figure 9.4
Expected # of times people/materials move between departments
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
41
Area A Area B Area C
Area D Area E Area F
60’
40’
Process Layout Example
Receiving Shipping Testing
Department Department Department
(4) (5) (6)
Figure 9.5
Assembly Painting Machine Shop
Department Department Department
(1) (2) (3)
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
42
Total # of ways to arrange 6 departments across 6 areas?
6! = 6x5x4x3x2x1 = 720 ways
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Process Layout Example
Interdepartmental Flow Graph
Figure 9.6
100
50
20
50
50
20
10
100
30
Machine Shop (3)
Testing
(6)
Shipping
(5)
Receiving
(4)
Assembly
(1)
Painting
(2)
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
44
Process Layout Example
Cost = ($1x$50) + ($2x$100) + ($2x$20) (1 and 2) (1 and 3) (1 and 6)
+ ($1x$30) + ($1x$50) + ($1x$10) (2 and 3) (2 and 4) (2 and 5)
+ ($2x$20) + ($1x$100) + ($1x$50) (3 and 4) (3 and 6) (4 and 5)
= $570
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
45
| Pair | Loads (X) | Cost to move loads (C) | Cost (XC) |
| 1 to 2 | 50 | 1 | 50 |
| 1 to 3 | 100 | 2 | 200 |
| 1 to 4 | 0 | 1 | 0 |
| 1 to 5 | 0 | 2 | 0 |
| 1 to 6 | 20 | 2 | 40 |
| 2 to 3 | 30 | 1 | 30 |
| 2 to 4 | 50 | 1 | 50 |
| 2 to 5 | 10 | 1 | 10 |
| 2 to 6 | 0 | 1 | 0 |
| 3 to 4 | 20 | 2 | 40 |
| 3 to 5 | 0 | 1 | 0 |
| 3 to 6 | 100 | 1 | 100 |
| 4 to 5 | 50 | 1 | 50 |
| 4 to 6 | 0 | 2 | 0 |
| 5 to 6 | 0 | 1 | 0 |
| $570 |
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Area A Area B Area C
Area D Area E Area F
60’
40’
Revised layout
Receiving Shipping Testing
Department Department Department
(4) (5) (6)
Painting Assembly Machine Shop
Department Department Department
(2) (1) (3)
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
47
Process Layout Example
Revised Interdepartmental Flow Graph
30
50
20
50
10
20
50
100
100
Machine Shop (3)
Testing
(6)
Shipping
(5)
Receiving
(4)
Painting
(2)
Assembly
(1)
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
48
Process Layout Example
Cost = ($1x$50) + ($1x$100) + ($1x$20) (1 and 2) (1 and 3) (1 and 6)
+ ($2x$20) + ($1x$50) + ($1x$10) (2 and 3) (2 and 4) (2 and 5)
+ ($2x$20) + ($1x$100) + ($1x$50) (3 and 4) (3 and 6) (4 and 5)
= $480
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
49
| Pair | Loads (X) | Cost to move loads (C) | Cost (XC) |
| 1 to 2 | 50 | 1 | 50 |
| 1 to 3 | 100 | 1 | 100 |
| 1 to 4 | 0 | 1 | 0 |
| 1 to 5 | 0 | 1 | 0 |
| 1 to 6 | 20 | 1 | 20 |
| 2 to 3 | 30 | 2 | 60 |
| 2 to 4 | 50 | 1 | 50 |
| 2 to 5 | 10 | 1 | 10 |
| 2 to 6 | 0 | 2 | 0 |
| 3 to 4 | 20 | 2 | 40 |
| 3 to 5 | 0 | 1 | 0 |
| 3 to 6 | 100 | 1 | 100 |
| 4 to 5 | 50 | 1 | 50 |
| 4 to 6 | 0 | 2 | 0 |
| 5 to 6 | 0 | 1 | 0 |
| $480 |
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Computer Software
Graphical approach only works for small problems
Computer programs are available to solve bigger problems
CRAFT
ALDEP
CORELAP
Factory Flow
Proplanner
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
51
Computer Software
Proplanner analysis
Distance traveled reduced by 38%
Before
After
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Computer Software
Three dimensional visualization software allows managers to view possible layouts and assess process, material handling, efficiency, and safety issues
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Work Cells (Cellular Layout)
Work Cells: an arrangement of machines and personnel that focuses on making a single product or family of related product.
Cells can be reconfigured as designs or volume changes
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
54
Work Cells (Cellular Layout)
An example of work cell would be in the production of a metallic case part that arrives at the factory from the vendor in separate pieces, requiring assembly.
First, the pieces would be moved from storage to the cell, where they would be welded together, then polished, then coated, and finally packaged. All of these steps would be completed in a single cell.
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
55
Cellular Layout
Process (Functional) Layout
Group (Cellular) Layout
Similar resources placed together
Resources to produce similar products placed together
T
T
T
M
M
M
T
M
SG
CG
CG
SG
D
D
D
D
T
T
T
CG
CG
T
T
T
SG
SG
M
M
D
D
D
M
M
D
D
D
A cluster or cell
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
56
Advantages of Work Cells
Reduce work-in-process inventory
Less floor space required
Reduce raw material and finished goods inventories
Enhance employee participation
Increase equipment and machinery utilization
Reduced investment in machinery and equipment
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
57
Requirements of Work Cells
Identification of families of products
A high level of training, flexibility and empowerment of employees
Being self-contained, with its own equipment and resources
Test (poka-yoke) at each station in the cell
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
58
Improving Layouts Using Work Cells
Current layout - workers in small closed areas.
Improved layout - cross-trained workers can assist each other. May be able to add a third worker as additional output is needed.
Figure 9.9 (a)
Material
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
59
Improving Layouts Using Work Cells
Current layout - straight lines make it hard to balance tasks because work may not be divided evenly
Improved layout - in U shape, workers have better access. Four cross-trained workers were reduced to three.
Figure 9.9 (b)
U-shaped line may reduce employee movement and space requirements while enhancing communication, reducing the number of workers, and facilitating inspection
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
60
Key definition
Takt time: pace of production to meet customer demands.
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Key definition
Cycle Time: the maximum time that a product is allowed at each workstation
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Staffing and Balancing Work Cells
Determine the number of operators required
Workers required =
Total operation time required
Takt time
Determine the takt time
Takt time =
Total work time available
Units required to satisfy customer demand
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
63
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
Standard time required
Operations
Assemble
Paint
Test
Label
Pack for
shipment
60
50
40
30
20
10
0
Figure 9.10
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
64
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 sec
Takt time = (8 hrs x 60 mins) / 600 units
= .8 min = 48 seconds
Workers required =
Total operation time required
Takt time
= 140 / 48 = 2.92 = 3 workers
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
65
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
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
66
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
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
67
Repetitive and Product-Oriented Layout
Volume is adequate for high equipment utilization
Product demand is stable enough to justify high investment in specialized equipment
Product is standardized or approaching a phase of life cycle that justifies investment
Supplies of raw materials and components are adequate and of uniform quality
The four preconditions to establishing layout for high-volume, low-variety products
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
68
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
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
69
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
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
70
Product-Oriented Layouts
Low variable cost per unit
Low material handling costs
Reduced work-in-process inventories
Easier training and supervision
Rapid throughput
Advantages
High volume is required
Work stoppage at any point ties up the whole operation
Lack of flexibility in product or production rates
Disadvantages
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
71
McDonald's Assembly Line
Figure 9.11
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Assembly-Line Balancing
Objective is to minimize the imbalance between machines or personnel while meeting required output
Starts with the precedence relationships
Determine cycle time
Calculate theoretical minimum number of workstations
Balance the line by assigning specific tasks to workstations
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
73
| TABLE 9.2 | Precedence Data for Wing Component | |||||
| TASK | ASSEMBLY TIME (MINUTES) | TASK MUST FOLLOW TASK LISTED BELOW | ||||
| A | 10 | – | ||||
| B | 11 | A | ||||
| C | 5 | B | ||||
| D | 4 | B | ||||
| E | 10 | A | ||||
| F | 3 | C, D | ||||
| G | 7 | F | ||||
| H | 11 | E | ||||
| I | 3 | G, H | ||||
| Total time | 64 |
Wing Component Example
This means that tasks B and E cannot be done until task A has been completed
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
74
| TABLE 9.2 | Precedence Data for Wing Component | ||||
| TASK | ASSEMBLY TIME (MINUTES) | TASK MUST FOLLOW TASK LISTED BELOW | |||
| A | 10 | – | |||
| B | 11 | A | |||
| C | 5 | B | |||
| D | 4 | B | |||
| E | 10 | A | |||
| F | 3 | C, D | |||
| G | 7 | F | |||
| H | 11 | E | |||
| I | 3 | G, H | |||
| Total time | 64 |
Wing Component Example
I
G
F
C
D
H
B
E
A
10
11
10
5
4
3
7
11
3
480 available mins per day
40 units required
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
75
480 available mins per day
40 units required
| TABLE 9.2 | Precedence Data for Wing Component | ||||
| TASK | ASSEMBLY TIME (MINUTES) | TASK MUST FOLLOW TASK LISTED BELOW | |||
| A | 10 | – | |||
| B | 11 | A | |||
| C | 5 | B | |||
| D | 4 | B | |||
| E | 10 | A | |||
| F | 3 | C, D | |||
| G | 7 | F | |||
| H | 11 | E | |||
| I | 3 | G, H | |||
| Total time | 64 |
Wing Component Example
I
G
F
C
D
H
B
E
A
10
11
11
5
4
3
7
11
3
Figure 9.12
Cycle time =
Production time available per day
Units required per day
= 480 / 40
= 12 minutes per unit
Minimum number of workstations
= 64 / 12
= 5.33, or 6 stations
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
76
| Layout Heuristics That May Be Used to Assign Tasks to Workstations in Assembly-Line Balancing | |
| 1. Longest task time | From the available tasks, choose the task with the largest (longest) task time |
| 2. Most following tasks | From the available tasks, choose the task with the largest number of following tasks |
| 3. Ranked positional weight | From the available tasks, choose the task for which the sum of following task times is the longest |
| 4. Shortest task time | From the available tasks, choose the task with the shortest task time |
| 5. Least number of following tasks | From the available tasks, choose the task with the least number of subsequent tasks |
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
77
Wing Component Example
Station 1
Station 2
Station 3
Station 5
Station 3
Station 4
Station 6
Station 6
I
G
F
H
C
D
B
E
A
10
11
10
5
4
3
7
11
3
Figure 9.13
480 available mins per day
40 units required
Cycle time = 12 mins
Minimum workstations
= 6
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
78
| TABLE 9.2 | Precedence Data for Wing Component | ||||
| TASK | ASSEMBLY TIME (MINUTES) | TASK MUST FOLLOW TASK LISTED BELOW | |||
| A | 10 | – | |||
| B | 11 | A | |||
| C | 5 | B | |||
| D | 4 | B | |||
| E | 11 | A | |||
| F | 3 | C, D | |||
| G | 7 | F | |||
| H | 11 | E | |||
| I | 3 | G, H | |||
| Total time | 65 |
Wing Component Example
I
G
F
C
D
H
B
E
A
10
11
11
5
4
3
7
11
3
480 available mins per day
40 units required
Cycle time = 12 mins
Minimum workstations
= 6
Efficiency =
∑ Task times
(Actual number of workstations) x (Largest cycle time)
= 64 minutes / ((6 stations) x (12 minutes))
= 88.89%
Idle Time = ((6 stations) × (12 minutes)) – 64 minutes = 8 minutes
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
79
Layout at Arnold Palmer Hospital´s New Facility (7 layouts)
https://www.youtube.com/watch?v=MWWsSUWWowc&index=96&list=PLQQrEJuJbVzddxf_T7Kw1oG9qldGpwjVs&t=0s
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Office Layout
https://www.youtube.com/watch?v=d67nLyjN4hQ&index=32&list=PLQQrEJuJbVzddxf_T7Kw1oG9qldGpwjVs
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Supermarket layout
https://www.youtube.com/watch?v=RjgkQ6bq7aE&list=PLQQrEJuJbVzddxf_T7Kw1oG9qldGpwjVs&index=30
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Amazon warehouse
https://www.youtube.com/watch?v=Y-lBvI6u_hw&index=31&list=PLQQrEJuJbVzddxf_T7Kw1oG9qldGpwjVs
FYI
9 - ‹#›
Copyright © 2017 Pearson Education, Ltd.
Copyright © 2017 Pearson Education, Ltd.
9 - ‹#›
Minimize cost = XijCij j=1
n
∑ i=1
n
∑
Minimize cost= X
ij
C
ij
j=1
n
å
i=1
n
å
Cost = XijCij j=1
n
∑ i=1
n
∑
Cost= X
ij
C
ij
j=1
n
å
i=1
n
å
Cost = XijCij j=1
n
∑ i=1
n
∑
Cost= X
ij
C
ij
j=1
n
å
i=1
n
å
= Time for task i
i=1
n
∑ Cycle time
=
Time for task i
i=1
n
å
Cycle time