Lecture Fundamentals of operations management (4/e): Chapter 11 - Davis, Aquilano, Chase

Chapter 8 Facility decisions: Layouts, after studying this chapter you will be able to: Introduce the different types of facility layouts that can be used in designing manufacturing and service operations, present a methodology for designing a process-oriented layout, introduce the concept of takt time and its relationship to the output capacity of a product-oriented layout,...

DAVIS AQUILANO CHASE

PowerPoint Presentation by Charlie Cook

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8–2

Chapter Objectives

Chapter Objectives

• Introduce the different types of facility layouts that can

be used in designing manufacturing and service

operations

• Present a methodology for designing a

process-oriented layout

• Introduce the concept of takt time and its relationship

to the output capacity of a product-oriented layout

• Identify the various steps and elements that are

involved in balancing an assembly line

• Discuss the current trends in facility layouts given

today’s shorter product life cycles and the customer’s increasing desire for customized products

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compete in the market and its long-term success

• Developing estimates of the investment costs of time and money associated with installing a particular

layout

• Attaining the goal of a smooth flow of material through the process through the choice of a layout that is both efficient and effective

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Types of Manufacturing Layouts

Types of Manufacturing Layouts

Layout Type

Process Similar operations are performed in a

common or functional area, regardless of the product in which the parts are used

interests

Fixed-Position The product, because of its size and/or

weight, remains in one location and processes are brought to it

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Characteristics of a Good Layout

Characteristics of a Good Layout

Exhibit 8.1

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Interdepartmental Flow

Interdepartmental Flow

Exhibit 8.2

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Building Dimensions and Departments

Building Dimensions and Departments

Exhibit 8.3

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Interdepartmental Flow Graph with Number of Annual Movements

Interdepartmental Flow Graph with Number of Annual Movements

Exhibit 8.4

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Cost Matrix—First Solution Cost Matrix—First Solution

Exhibit 8.5

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Cost Matrix—Second Solution Cost Matrix—Second Solution

Exhibit 8.7

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Revised Building Layout Revised Building Layout

Exhibit 8.8

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Product Layout

Product Layout

• Assembly Lines

–A progressive paced assembly linked by some

sort of material handling device.

• Assembly Line Type Differences

–Material handling devices

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Product Layout: Key Terms

Product Layout: Key Terms

• Product Interval Time

–The time between products being completed

(processed through) at a single station (process

step) Also cycle time or takt time.

• Product Duration (Throughput) Time.

–The overall time required to entirely complete an

individual product.

• Assembly Line Balancing

–Assignment of tasks to workstations within a

given cycle time and with minimum idle worker time.

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2 Determine the required takt (T) time

3 Determine the theoretical minimum number of

workstations (Nt) required to satisfy the takt time constraint

4 Select a primary rule by which tasks are to be

assigned to workstations and a secondary rule to break ties

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6 Evaluate the efficiency of the resulting assembly line

7 If efficiency is unsatisfactory, rebalance the line using

a different decision rule in step 4

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Matching task time to takt time:

1 Split the task

2 Duplicate the station

3 Share the task

4 Use a more skilled worker

5 Work overtime

6 Redesign the product

Exhibit 8.9

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Assembly Line Balancing Formulas

Assembly Line Balancing Formulas

units) (in 

day  per 

Output 

day per 

   time

Production  

Number of workstations

Takt time (T)

of number  Actual

Sum of task times (S)

Efficiency

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Assembly Steps and Times for Model J Wagon

Assembly Steps and Times for Model J Wagon

Exhibit 8.10

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Precedence Graph for Model J Wagon

Precedence Graph for Model J Wagon

Exhibit 8.11

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A Balance Made According to  Largest Number of Following Tasks Rule

A Balance Made According to  Largest Number of Following Tasks Rule

Exhibit 8.12a

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Precedence Graph for Model J Wagon

Precedence Graph for Model J Wagon

Exhibit 8.12B

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0 4

50 5

195

or Efficiency

NT S Efficiency

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Source: Robert W Hall, Attaining Manufacturing Excellence

(Homewood, IL: Dow Jones-Irwin, 1987), p 125.

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Group Technology (Cellular) Layout

Group Technology (Cellular) Layout

• Benefits

–Better human relations in small work teams.

–Improved operator expertise from the limited

number of parts and quick production cycle.

–Less work-in-process inventory and material

handling due to reduced number of production stages

–Faster production setup from faster tooling

changes.

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Group Technology (GT) Layout

Group Technology (GT) Layout

• Developing a GT Layout

–Grouping parts into families that follow a

common sequence of steps.

–Identifying dominant flow patterns of

parts-families for location of processes.

–Physically grouping machines and processes

into cells.

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Facilities Layout for Services

Facilities Layout for Services

• Goals of Service Facility Layouts

–Minimize travel time for workers and customers –Maximize revenues from customers

• Types of Service Layouts

–Process layout—emergency rooms

–Product layout—cafeteria line

–Fixed-position layout—automobile repair shop

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Facilities Layout for Services

Facilities Layout for Services

• Servicescape

–The aspects of the physical surroundings in a

service operation that can affect a customer’s perception of the service received.

–Ambient conditions

• Noise, lighting, and temperature

–Spatial layout and functionality

• Minimizing employee travel time and maximizing

revenue opportunities from customers

–Signs, symbols, and artifacts

• Objects that create positive images of the firm