Tqm chap 6

• Facility layout


  The specific arrangement of physical facilities
• Facility layout studies are necessary when

  • A new facility is constructed
  • There is a significant change in demand or throughput volume
  • A new good or service is introduced to the customer benefit package
  • Different processes, equipment, and/or technology are installed
• Objectives of layout studies

  • Minimize delays in materials handling and customer movement
  • Maintain flexibility
  • Use labor and space effectively
  • Promote high employee morale and customer satisfaction
  • Minimize energy use and environmental impact
  • Provide for good housekeeping and maintenance
  • Enhance sales as appropriate in manufacturing and service facilities
• A good layout should support the ability of operations to accomplish its mission
• Four major layout patterns

  • Product layout
  • Process layout
  • Cellular layout
  • Fixed-position layout
• Product layout


  An arrangement based on the sequence of operations that is performed during the manufacturing of a good or delivery of a service
• Advantages of product layouts

  • Higher output rates
  • Lower work-in-process inventories
  • Less materials handling
  • Higher labor and equipment utilization
  • Simple planning and control systems
• Disadvantages of product layouts

  • Breakdown of one piece of equipment can cause the entire process to shut down
  • Changes in product design or introduction of new products may require major changes in the layout, thus limiting flexibility
  • Less flexible and expensive to change
  • Usually require more costly, specialized equipment
  • Jobs may provide little job satisfaction due to high level of division of labor
• Process layout


  A functional grouping of equipment or activities that do similar work
• Examples of process layouts

  • Job shops
  • Legal offices
  • Shoe manufacturing
  • Jet engine turbine blades
  • Hospitals
• Advantages of process layouts

  • More flexibility
  • Generally require a lower investment in equipment
  • Failure of a piece of equipment generally does not affect the entire system
  • Diversity of jobs can lead to increased worker satisfaction
• Limitations of process layouts

  • Low equipment utilization
  • High materials-handling costs
  • More complicated planning and control systems
  • Higher worker skill requirements
• Cellular layout


  The design is based on self-contained groups of equipment (called cells) needed for producing a particular set of goods or services
• Example of a manufacturing cell

  • U-shaped arrangement of machines
• Benefits of cellular layouts


  • Facilitate the processing of families of parts with similar processing requirements
  • Reduce materials-handling requirements
  • Enable workers to concentrate on production rather than on moving parts between machines
  • Quicker response to quality problems within cells can improve the overall level of quality
  • Additional floor space becomes available for other productive uses
  • Workers have greater responsibility and become more aware of their contribution to the final product, increasing their morale and satisfaction and ultimately quality and productivity
• 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
• Examples of fixed-position layouts


  • Production of large items such as heavy machine tools, airplanes, buildings, locomotives, and ships
  • Major hardware and software installations
  • Sporting events
  • Concerts
• Characteristics of fixed-position layouts

  • Work-in-process remains stationary rather than moving from one work center to another
  • Usually require a high level of planning and control compared with other types of layouts
• Comparison of basic layout patterns

  • Demand volume
  • Equipment utilization
  • Automation potential
  • Setup/changeover requirements
  • Flexibility
  • Type of equipment
• The basic trade-off in selecting among layout types is flexibility versus productivity
• Service organizations use product, process, cellular, and fixed-position layouts to organize different types of work
• Product layouts in service organizations

  Tend to be used for highly standardized services
• Process layouts in service organizations

  Tend to be used for services that need the ability to provide a wide variety of services to customers with differing requirements
• The design of service facilities requires the clever integration of layout with the servicescape and process design to support service encounters
• Product layouts in flow shops generally consist of a fixed sequence of workstations
• 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
• Lack-of-work delay


  Occurs whenever one stage completes work and no units from the previous stage are awaiting processing
• These sources of delay can be minimized by attempting to "balance" the process by designing the appropriate level of capacity at each workstation
• Assembly line


  A product layout dedicated to combining the components of a good or service that has been created previously
• Assembly lines were pioneered by Henry Ford and are vital to economic prosperity and are the backbone of many industries such as automobiles and appliances
• Assembly-line balancing


  A technique to group tasks among workstations so that each workstation has—in the ideal case-the same amount of work
• The objective of assembly-line balancing is to minimize the imbalance among workstations while trying to achieve a desired output rate
• To begin assembly-line balancing, we need to know the set of tasks to be performed and the time required to perform each task, the precedence relations among the tasks, and the desired output rate or forecast of demand for the assembly line
• Assembly-line balancing


  A management policy issue where management must decide whether to produce exactly to the forecast, overproduce and hold inventory, subcontract, and so on
• Assembly-line balancing example


  1. Task A (0.5 min)

  2. Task B (0.3 min)

  3. Task C (0.2 min)
• Total time required to complete one part is 0.5 + 0.3 + 0.2 = 1.0 minute
• If one worker performs all three tasks in sequence, they could produce 480 parts/day
• Alternative with three workers, each performing one task

  1. Worker 1 (120 parts/hour)

  2. Worker 2 (1,600 parts/day)

  3. Worker 3 (2,400 parts/day)
• Maximum output with three workers is 960 parts/day, as Worker 1 performing Task A is the bottleneck
• Alternative with two workstations

  1. Workstation 1 performs Task A (0.5 min)

  2. Workstation 2 performs Tasks B and C (0.5 min)