© Wiley 2007 Chapter 10 – Facility Layout Operations Management by R. Dan Reid & Nada R. Sanders 3rd Edition © Wiley 2007 PowerPoint Presentation by R.B. Clough – UNH M. E. Henrie - UAA
© Wiley 2007
Chapter 10 – Facility Layout
Operations Managementby
R. Dan Reid & Nada R. Sanders3rd Edition © Wiley 2007
PowerPoint Presentation by R.B. Clough – UNHM. E. Henrie - UAA
© Wiley 2007
Learning Objectives
Define layout planning and its importance
Identify and describe different types of layouts
Compare process layouts & product layouts
Describe the steps involved in designing a process layout
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Learning Objectives - continued
Describe the steps involved in designing a product layout
Explain the advantages of hybrid layouts
Define the meaning of group technology (cell) layouts
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What Is Layout Planning Layout planning is determining the best physical
arrangement of resources within a facility Facility resource arrangement can significantly affect
productivity Two broad categories of operations:
Intermittent processing systems – low volume of many different products
Continuous processing systems – high volume of a few standardized products
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Types of Layouts
Four basic layout types consisting of; Process layouts - Group similar resources
together Product layouts - Designed to produce a
specific product efficiently Hybrid layouts - Combine aspects of both
process and product layouts Fixed-Position layouts - Product is two large
to move; e.g. a building
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Process Layouts Process layout unique characteristics
include;
General purpose & flexible resources
Facilities are more labor intensive
Lower capital intensity & automation
Higher labor intensity
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Process Layouts - continued Processing rates are slower
Material handling costs are higher
Scheduling resources & work flow is more complex
Space requirements are higher
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Product Layouts
Product layout unique characteristics are Produce small number of products
efficiently Resources are specialized High capital intensity Low flexibility relative to the market
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Product Layouts - continued
Processing rates are faster
Material handling costs are lower
Lower space requirements
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Hybrid Layouts Combine elements of both product &
process layouts Maintain some of the efficiencies of
product layouts Maintain some of the flexibility of process
layouts
Examples: Group technology & manufacturing cells Grocery stores
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Fixed-Position Layout
Used when product is large Product is difficult or impossible to
move, i.e. very large or fixed All resources must be brought to
the site Scheduling of crews and resources
is a challenge
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Designing Process Layouts Step 1: Gather information:
Space needed, space available, importance of proximity between various units
Step 2: Develop alternative block plans: Using trial-and-error or decision support tools
Step 3: Develop a detailed layout Consider exact sizes and shapes of
departments and work centers including aisles and stairways
Tools like drawings, 3-D models, and CAD software are available to facilitate this process
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Process Layout Steps Step 1: Gather information like space needed, from-to
matrix, and REL Chart for Recovery First Sports Medicine Clinic (total space 3750 sq. ft.)
ARadiology
400 sq. ft.
BLaboratory
300 sq. ft.
CLobby & Waiting
300 sq. ft.
DExamining
Rooms800 sq. ft.
ESurgery & Recovery900 sq. ft.
FPhysical Therapy
1050 sq. ft.
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Step 1: Gather Information
(continued)
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Step 2: Develop a New Block Layout Use trial and error with from-to and REL Charts as a guide Use computer software like ALDEP or CRAFT
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Decision Support Tools Trial and error method good for simple
problems Layout problems are combinatorial,
3x2 office layout has 6! Options (6*5*4*3*2*1 = 720 options)
Computer programs are available decision support tools ALDEP based on REL and CRAFT based on
form-to matrix
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Special Cases of Process Layouts
There are a number of unique process layouts which include
Warehouse layouts
Office Layouts
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Warehouse Layouts
Warehouse Layout Considerations: Primary decision is where to locate each
department relative to the dock Departments can be organized to minimize “ld”
totals Departments of unequal size require
modification of the typical ld calculations to include a calculation of the “ratio of trips to area needed”
The usage of “Crossdocking” modifies the traditional warehouse layouts; more docks, less storage space, and less order picking
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Office Layouts Office Layout Considerations:
Almost half of US workforce works in an office environment
Human interaction and communication are the primary factors in designing office layouts
Layouts need to account for physical environment and psychological needs of the organization
One key layout trade-off is between proximity and privacy
Open concept offices promote understanding & trust
Flexible layouts incorporating “office landscaping” help to solve the privacy issue in open office environments
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Designing Product Layouts Product layouts are different than process
layouts Product layouts provide for sequential product
movement that enhances efficiency Designing product layouts requires
consideration of Sequence of tasks to be performed by each
workstation Logical order Speed considerations – line balancing
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Designing Product Layouts - continued
Step 1: Identify tasks & immediate predecessors Step 2: Determine the desired output rate Step 3: Calculate the cycle time Step 4: Compute the theoretical minimum number of workstations Step 5: Assign tasks to workstations (balance the line) Step 6: Compute efficiency, idle time & balance delay
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Step 1: Identify Tasks & Immediate PredecessorsExample 10.4 Vicki's Pizzeria and the Precedence Diagram
Immediate Task TimeWork Element Task Description Predecessor (seconds
A Roll dough None 50B Place on cardboard backing A 5C Sprinkle cheese B 25D Spread Sauce C 15E Add pepperoni D 12F Add sausage D 10G Add mushrooms D 15H Shrinkwrap pizza E,F,G 18I Pack in box H 15
Total task time 165
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Layout Calculations
Step 2: Determine output rate Vicki needs to produce 60 pizzas per hour
Step 3: Determine cycle time The amount of time each workstation is
allowed to complete its tasks
Limited by the bottleneck task (the longest task in a process):
sec./unit 60
units/hr 60
sec/min 60x min/hr 60
units/hroutput desired
sec./day time available)(sec./unit time Cycle
hourper pizzasor units/hr, 72sec./unit 50
sec./hr. 3600
time task bottleneck
time availableoutput Maximum
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Layout Calculations (continued)
Step 4: Compute the theoretical minimum number of stations TM = number of stations needed to
achieve 100% efficiency (every second is used)
Always round up (no partial workstations)
Serves as a lower bound for our analysis
stations 3or 2.75,
nsec/statio 60
seconds 165
time cycle
times taskTM
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Layout Calculations (continued)
Step 5: Assign tasks to workstations Start at the first station & choose the longest eligible task
following precedence relationships Continue adding the longest eligible task that fits without going
over the desired cycle time When no additional tasks can be added within the desired cycle
time, begin assigning tasks to the next workstation until finishedWorkstation Eligible task Task Selected Task time Idle time
A A 50 10
B B 5 5
C C 25 35
D D 15 20
E, F, G G 15 5
E, F E 12 48
F F 10 38
H H 18 20
I I 15 5
1
2
3
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Last Layout Calculation Step 6: Compute efficiency and balance
delay Efficiency (%) is the ratio of total
productive time divided by total time
Balance delay (%) is the amount by which the line falls short of 100%
91.7%100sec. 60x stations 3
sec. 165
NC
t (%) Efficiency
8.3%91.7%100%delay Balance
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Other Product Layout Considerations
Shape of the line (S, U, O, L): Share resources, enhance communication &
visibility, impact location of loading & unloading
Paced versus un-paced lines Paced lines use an automatically enforced cycle
time
Number of products produced Single Mixed-model lines
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Designing Hybrid Layouts One of the most popular hybrid layouts uses
Group Technology (GT) and a cellular layout GT has the advantage of bringing the efficiencies
of a product layout to a process layout environment
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Process Flows before the Use of GT Cells
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Process Flows after the Use of GT Cells
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Facility Layout Across the Organization
Layout planning is organizationally important for an efficient operations Marketing is affected by layout especially
when clients come to the site Human resources is affected as layout
impacts people Finance is involved as layout changes can
be costly endeavors
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Chapter 10 Highlights Layout planning is deciding on the best physical
arrangement of all resources that consumes space within a facility. Proper layout planning is highly important for the efficient running of a business. Otherwise, there can be much wasted time and energy, as well as confusion.
There are four basic types of layouts: process, product, hybrid, and fixed position. Process layouts group resources based on similar processes. Product layouts arrange resources in straight-line fashion. Hybrid layouts combine elements of both process and product layouts. Fixed-position layouts occur when the product is larger and cannot be moved.
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Chapter 10 Highlights - continued
Process layouts provide much flexibility and allow for the production of many products with differing characteristics. Product layouts, on the other hand, provide greater efficiency when producing one type of product.
The steps for designing process layouts are (1) gather information about space needs, space availability, and closeness requirements of departments; (2) developing a block plan or schematic of the layout; and (3) developing a detailed layout.
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Chapter 10 Highlights - continued
The steps for designing an product layout are (1) identify tasks that need to be performed and their immediate predecessors; (2) determine output rate; (3) determine cycle time; (4) computing the theoretical minimum number of work stations, (5) assigning tasks to workstations; and (6) computing efficiency and balance delay.
Hybrids layouts have advantages over other layout types because they combine elements of both process and product layouts to increase efficiency.
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Chapter 10 Highlights - continued
An example of hybrid layouts is group technology or cell layouts. Group technology is the process of crating groupings of products based on similar processing requirements. Cells are created for each grouping of products, resulting in a more orderly flow of products through the facility.
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