1. Chapter 10 – Facility Layout
Operations Management by
R. Dan Reid & Nada R. Sanders
3rd Edition © Wiley 2007

2. 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 both process and product layouts
Explain the advantages of hybrid layouts
Define the meaning of group technology & its importance to cellular layouts

3. 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

4. Facility Layout Fixed Position Process Product
Product is too large to move;
e.g.: a building
Process
Group similar resources together
Product
Designed to produce a specific product efficiently
Hybrid: combines aspects of both process and product layouts
Cellular
Modular

5. Fixed Position Layout
The position of a product or customer is fixed; and materials, equipment, workers, and other resources are transported to and from the product or customer.
Usually used because product movement is difficult (ship building) or for convenience (on-site repair).
This is often managed through Project Management (Chapter 16).

6. Process Layout
Similar processes/functions are grouped together (job shop). Volume of parts/services does not warrant product or cellular layout.
Primary advantages--flexibility, utilization of machinery/equipment.
Disadvantages--greater handling of materials/customers, more complex scheduling, WIP/waiting lines, departmental boundaries

7. Traditional Process Layout

8. Process Layouts General purpose & flexible resources
Lower capital intensity & automation
Higher labor intensity
Resources have greater flexibility
Processing rates are slower
Material handling costs are higher
Scheduling resources & work flow is more complex
Space requirements are higher

9. 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

10. Comparing Alternatives
Load-distance measures
Load: # of trips, weight moved, $-value moved
Distance: rectilinear distance (using north-south & east-west movements)
REL charts:
Management opinion on strength of relationships
Software tools:
CRAFT: computerized relative allocation of facilities technique
ALDEP: automated layout design program

11. Process Layout Example

12. 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.) A
Radiology
400 sq. ft. B
Laboratory
300 sq. ft. C
Lobby & Waiting D
Examining Rooms
800 sq. ft. E
Surgery & Recovery
900 sq. ft. F
Physical Therapy
1050 sq. ft.

13. Step 1: Gather Information (continued)

14. Step 2: Develop a Block Layout
Use trial and error with from-to and REL Charts as a guide
Use computer software like ALDEP or CRAFT

15. 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” (see Ch.4) modifies the traditional warehouse layouts; more docks, less storage space, and less order picking

16. 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

17. Product Layout
Processes/work stations arranged in sequence of activities required to produce the product/service (Assembly Line).
Use for high volume, standardized products and services
WIP and handling of materials/customers is minimized
Equipment is specialized, capital intensive
Output is dependent on the slowest work station
The “line” must be balanced for effectiveness.

18. Product Layouts Specialized equipment
High capital intensity & wide use of automation
Processing rates are faster
Material handling costs are lower
Less space required for inventories
Less volume or design flexibility

19. Product Layout Product A Product B Product C Step 1 Step 2 Step 3
7-14

20. Designing Product Layouts
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

21. Assembly Line Balancing
Precedence diagram: circles=tasks, arrows show the required sequence.
Determine cycle time:
Determine required workstations (theoretical minimum)
Set rules for assigning tasks (number of following tasks, longest task time)

22. Assembly Line Balancing
Assign tasks to first workstation, using rules and staying within cycle time. Repeat for following workstations until all tasks are assigned.
Evaluate line efficiency:
Rebalance if efficiency is not satisfactory.

23. Step 1: Identify Tasks & Immediate Predecessors

24. 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):

25. 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

26. 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 finished

27. 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%

28. 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

29. Comparison of Product vs. Product Layouts
Process Layouts Product Layouts
Products: large #, different small # efficiently
Resources: general purpose specialized
Facilities: more labor intensive more capital intensive
Flexibility: greater relative to market lower relative to market
Processing slower faster
Rates:
Handling costs: high low
Space requirements: higher lower

30. 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

31. Hybrid Layouts Cellular Layout Modular Layout
Cross between product/process layout
group a number of machines into a cell to produce a family of parts requiring similar processing (group technology).
Often arranged into U- or C-shaped line flows
Modular Layout
achieves layout flexibility so that layouts can be changed, expanded, or reduced without much difficulty.

32. 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

33. Process Flows before the Use of GT Cells

34. Process Flows after the Use of GT Cells

35. 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

36. Chapter 10 Highlights
Layout planning is deciding on the best physical arrangement of resources.
There are four basic types of layouts: process, product, hybrid, and fixed position.
Process layouts provide flexibility to make a variety of different products. Product layouts provide greater efficiency for one product.
The steps for designing process layouts are: gather space and closeness information, develop a block plan, and develop a detailed layout.

37. Chapter 10 Highlights (continued)
The steps for designing an product layout are: identify tasks and predecessors, determine output rate, determine cycle time, computing the theoretical minimum number of work stations, assigning tasks to workstations, and computing efficiency and balance delay.
Hybrids layouts combine elements from both types of layouts to increase efficiency.
Hybrid layouts combine GT analysis with cellular layout concepts .

38. Chapter 10 Homework Hints
10.8: Assign sites based on number of trips (refer to Example 10.2). There is no strategy regarding which side of the aisle to assign—just nearness to the dock.
10.16: Follow the steps. This is a product layout (assembly line balancing). The book has an example on pages , which is also on the slides covered in class.

39. Sample Problem—10.7 Department Category Trips to/from dock 1
Sports t-shirts 50 2
Men’s t-shirts 63 3
Women’s t-shirts 35 4
Children’s t-shirts 55 5
Fashion t-shirts 48 6
Undershirts 60

40. Sample Problem –10.15 Task Imm. predecessor Task time (sec)
None 55 B 30 C 22 D 35 E
B, C 50 F 15 G 5 H 10
TOTAL
222
Draw precedence diagram
Determine cycle time—demand = 50 units/hr
Theoretical minimum no. of work stations
Assign tasks to workstations using cycle time
Efficiency and balance delay of line?
Bottleneck?
Maximum output?