OM Chapter 08

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FACILITY AND WORK DESIGNCHAPTER 8

DAVID A. COLLIERAND

JAMES R. EVANS

LO1 Describe four layout patterns and when they should be used.

LO2 Explain how to design product layouts using assembly line balancing.

LO3 Explain the concepts of process layout.LO4 Describe issues related to workplace design. LO5 Describe the human issues related to

workplace design.

l e a r n i n g o u t c o m e s

Chapter 8 Learning Outcomes

rofessor Frey had just taken his operations management class on a tour of Honda’s automobile plant in Marysville, Ohio. During the tour, the students had a chance to see how the facility design helped to improve the efficiency of the assembly processes for the automobilesand motorcycles they manufacture. The students were also very impressed with the level of teamwork among the employees. In the following class debriefing, Steve stated that he didn’t realize how important the design of the facility was in promoting teamwork and assuring quality. Arun couldn’t believe that they could produce so many different models in any order on the same assembly lines. Kate observed that the entire facility shows an image of safety, efficiency, professionalism, cleanliness, quality, and excitement. “In the factory, everything has its correct place. The workers know where everything is. The facility is spotless, a lot different from my dad’s machine shop.” Without hesitation she said, “Wow, I think I’ll buy a Honda!”

Chapter 8 Facility and Work Design

What do you think? Think of a facility in which you have conducted business – for instance, a restaurant, bank, or automobile dealership. How did the physical environment and layout enhance or degrade your customer experience?

Facility layout refers to the specific arrangement of physical facilities. Facility-layout studies are necessary whenever: 1. a new facility is constructed, 2. there is a significant change in demand or

throughput volume, 3. a new good or service is introduced to the

customer benefit package, or 4. different processes, equipment, and/or

technology are installed.

Purposes of layout studies are to: • minimize delays in materials handling and

customer movement • maintain flexibility • use labor and space effectively• promote high employee morale and customer

satisfaction• provide for good housekeeping and

maintenance• enhance sales as appropriate in

manufacturing and service facilities

Other Facility Layout Issues

• Essentially, a good layout should support the ability of operations to accomplish its mission.

• If the facility layout is flawed in some way, process efficiency and effectiveness suffers.

• In manufacturing, facility layout is generally unique, and changes can be accomplished without much difficulty.

Other Facility Layout Issues

• For service firms, however, the facility layout is often duplicated in hundreds or thousands of sites. This makes it extremely important that the layout be designed properly, as changes can be extremely costly.

• Also see Supply Chain Design for Multisite Services in Chapter 9.

Types of Facility Layouts

• A product layout is an arrangement based on the sequence of operations that are performed during the manufacturing of a good or delivery of a service.

• Examples: winemaking industry, credit card processing, Subway sandwich shops, paper manufacturers, insurance policy processing, and automobile assembly lines.

Product Layout• Advantages of product layouts include lower

work-in-process inventories, shorter processing times, less material handling, lower labor skills, and simple planning and control systems.

• Disadvantages include that a breakdown at one workstation can cause the entire process to shut down; a change in product design or the introduction of new products may require major changes in the layout, limiting flexibility.

Exhibit 8.1 Product Layout for Wine Manufacturer

• A process layout consists of a functional grouping of equipment or activities that do similar work.

• Examples: legal offices, shoe manufacturing, jet engine turbine blades, and hospitals use a process layout.

Process Layout• Advantages of process layouts include a

lower investment in equipment, and the diversity of jobs inherent in a process layout can lead to increased worker satisfaction.

• Disadvantages include high movement and transportation costs, more complicated planning and control systems, longer total processing time, higher in-process inventory or waiting time, and higher worker-skill requirements.

Exhibit 8.2 Process Layout for a Machine Shop

Cellular Layout

• In a cellular layout the design is not according to the functional characteristics of equipment, but rather by self-contained groups of equipment (called cells), needed for producing a particular set of goods or services.

• Group technology, or cellular manufacturing, classifies parts into families so that efficient mass-production-type layouts can be designed for the families of goods or services.

Cellular Layout

• Cellular layouts are used to centralize people expertise and equipment capability.

• Examples: groups of different equipment (called cells) needed for producing families of goods or services, group legal (labor law, bankruptcy, divorce, etc.), or medical specialties (maternity, oncology, surgery, etc.).

Exhibit 8.3

Source: J. T. Black, “Cellular Manufacturing Systems Reduce Set Up time, Make Small-Lot Production Economical,” Industrial Engineering Magazine, Nov. 1983. Used with permission from the author.

Cellular Manufacturing Layout

• A fixed-position layout consolidates the resources necessary to manufacture a good or deliver a service, such as people, materials, and equipment, in one physical location.

• The production of large items such as heavy machine tools, airplanes, buildings, locomotives, and ships is usually accomplished in a fixed-position layout.

Fixed-Position Layout

Fixed-Position Layout • This fixed-position layout is synonymous

with the "project" classification of processes presented in Chapter 7.

• Service-providing firms also use fixed-position layouts; examples include major hardware and software installations, sporting events, and concerts.

Exhibit 8.4 Comparison of Basic Layout Patterns

Facility Design in Service Organizations

Service organizations use product, process, cellular, and fixed-position layouts to organize different types of work. Process Layout ExamplesLibraries place reference materials, serials, and microfilms into separate areas; hospitals group services by function also, such as maternity, oncology, surgery, and X-ray; and insurance companies have office layouts in which claims, underwriting, and filing are individual departments.

Chapter 8 Facility Layout in Service Organizations

Facility Design in Service Organizations

Product Layout ExamplesService organizations that provide highly standardized services tend to use product layouts. For example, Exhibit 8.5 shows the layout of the kitchen at a small pizza restaurant that has both dine-in and delivery. Lenscrafters Uses Both Process and Product LayoutsIn Exhibit 6.10, we saw the customer contact area arranged in a process layout. In the lab area, however, where lenses are manufactured, a group layout is used.

Chapter 8 Facility Layout in Service Organizations

Exhibit 8.5 Product Layout for a Pizza Kitchen

Designing Product Layouts• A product layout is an arrangement based on

the sequence of operations that are performed during the manufacturing of a good or delivery of a service.

• Flow-blocking delay occurs when a work center completes a unit but cannot release it because the in-process storage at the next stage is full. The worker must remain idle until storage space becomes available.

• Lack-of-work delay occurs whenever one stage completes work and no units from the previous stage are awaiting processing.

Exhibit 8.6 A Typical Manufacturing Workstation Layout

Assembly-Line Balancing

• An assembly line is a product layout dedicated to combining the components of a good or service that has been created previously.

• Assembly line balancing is a technique to group tasks among workstations so that each workstation has—in the ideal case—the same amount of work.

• Examples: winemaking industry, credit card processing, Subway sandwich shops, paper manufacturers, insurance policy processing, and automobile assembly lines.

Chapter 8 Assembly Line Balancing

Assembly-Line Balancing

To begin, we need to know three types of information to balance an assembly line:

1. the set of tasks to be performed and the time required to perform each task,

2. the precedence relations among the tasks—that is, the sequence in which tasks must be performed, and

3. the desired output rate or forecast of demand for the assembly line.

Exhibit 8.7 A Three-Task Assembly Line

Cycle time is the interval between successive outputs coming off the assembly line. • In the three-operation example shown in

Exhibit 8.7, if we use only one workstation, the cycle time is 1 minute; that is, one completed assembly is produced every minute.

• If two workstations are used, the cycle time is 0.5 minute.

• If three workstations are used, the cycle time is still 0.5 minute, because task A is the bottleneck, or slowest operation. The line can produce only one assembly every 0.5 minute.

Cycle time is the interval between successive outputs coming off the assembly line. Cycle time is related to the output rate (R) by the following equation:

CT = A/R [8.2]

• A = available time to produce the output. • The output rate (R) is normally the demand

forecast, adjusted for on-hand inventory if appropriate, or orders released to the factory.

• Both A and R must have the same time units (hour, day, week, and so on).

Minimum number of workstations required = Sum of task times/Cycle time = t/CT [8.3]Total Time Available = (Number of work stations)(Cycle Time) = (N)(CT) [8.4]Total Idle Time = (N)(CT) − t [8.5]Assembly Line Efficiency = t/(N)(CT) [8.6]Balance Delay = 1 − Assembly Line Efficiency[8.7]

Exhibit 8.8 A Typical In-Line Skate

Exhibit 8.9 Precedence Network for In-Line Skate

Assembly Line Balance for In-Line Skate

Workstation Tasks Total Time Idle TimeA 1, 2, 5 5.7 0.3B 3, 4, 6, 7, 8 3.7 2.3

Total 9.4 2.6Using equations [8.4] to [8.6] we may compute the following:Total Time Available = (Number workstations)(Cycle Time) = (N)(CT) = (2)(6) = 12 minutesTotal Idle Time = (N)(CT) − t = (2)(6) - 9.4 = 2.6 minutesAssembly Line Efficiency = t/(N)(CT) = 9.4/(2)(6) = 78.3%

Chapter 8 Workplace Design

Workplace DesignExample questions that must be addressed at the workstation level include:1. Who will use the workplace? Will the

workstation be shared? How much space is required?

2. How will the work be performed? What tasks are required? How much time does each task take? How much time is required to setup for the workday or for a particular job? How might the tasks be grouped into work activities most effectively?

Workplace DesignExample questions that must be addressed at the workstation level include:3. What technology is needed? Employees may

need a computer or access to customer records and files, special equipment, intercoms, and other forms of technology.

4. What must the employee be able to see?5. What must the employee be able to hear?6. What environmental and safety issues need

to be addressed?

Exhibit 8.10 Pizza Preparation Workplace Design

• Ergonomics is concerned with improving productivity and safety by designing workplaces, equipment, instruments, computers, workstations, and so on that take into account the physical capabilities of people.

• A job is the set of tasks an individual performs.

• Job design involves determining the specific job tasks and responsibilities, the work environment, and the methods by which the tasks will be carried out to meet the goals of operations.

• Job enlargement is the horizontal expansion of the job to give the worker more variety—although not necessarily more responsibility.

• Job enrichment is vertical expansion of job duties to give the worker more responsibility.

• A team is a small number of people with complementary skills who are committed to a common purpose, set of performance goals, and approach for which they hold themselves mutually accountable.

Virtual Workplaces• About two-thirds of the U.S. workforce

collects, organizes, analyses, and disseminates information.

• Physical assets, such as paper and offices, are being replaced by virtual projects, offices, and workplaces.

• Check out Officescape: (www.officescape.com).

Exhibit 8.11 Precedence Diagram for Problem 8

Exhibit 8.12 Precedence Diagram for Problem 10

OM Chapter 08

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