Chapter 6 Process Selection and Facility Layout

1
Chapter 6 Process Selection and Facility Layout

• Process types and selection, automation, layout
  types, line balancing

2
Process Selection

• Make or buy analysis (See pp.185-186)
• QBEP FC / (p v)
• Process types (type of operations)
• Project
• Job
• Batch
• Repetitive
• Continuous flow
• Volume, mix, flexibility considerations

3
Why Automate?
4
Why Automate?

• Reduce or eliminate labor cost??
• Apply only to high volume operations??
• Keep up with the other CEOs at the Rotary Club??
• See the ads and say Wow, Ive got to have one
  of those!??

5
Why Automate?

• Quality
• Assures consistency, low variability
• Rapid change
• Shortens setups and changeovers
• Reduces time to turnaround prototypes
• Lower tooling cost
• Eliminates specialized tools and dies
• Reduced labor cost

6
Automation Concepts - 1

• Product design
• CADD computer aided drawing and drafting
• CAD computer aided design
• Process design
• CAPP computer aided process planning
• Machine control
• NC numerical control
• CNC computerized numerical control
• DNC direct numerical control
• FMS flexible manufacturing system
• CAM computer aided manufacturing

7
Automation Concepts - 2

• Production scheduling
• CAS computer aided scheduling
• Service
• CAI computer aided instruction
• Warehousing
• AS/RS automated storage and retrieval systems

8
Automation Concepts - 3

• Robotics
• Heavy use in auto industry
• Described in terms of number of axes of motion
  (up to 6)
• Arm sweep
• Shoulder swivel
• Elbow extension
• Pitch (wrist)
• Yaw (wrist)
• Roll (wrist)

9
Automation Concepts 4

• CIM computer integrated manufacturing
• Integrates all the preceding concepts
• MAP manufacturing automation protocol
• Major development in U.S. auto industry

10
Line Balancing Definitions

• Line balancing
• Balance work among production lines, or
• Balance tasks among workstations on 1 line
• Cycle time
• Materials Management time from beginning of
  first operation until completion of last
  operation, or
• Industrial Engineering time between completion
  of 2 units of product, or
• Line Balancing Maximum time allowed at each
  workstation

11
Line Balancing Tools

• Cycle time calculation
• Output capacity ( OC OT / CT )
• Where OT Operating Time per day, CT Cycle
  Time
• Cycle time ( CT OT/D )
• Where D Desired output rate
• Precedence diagrams
• Similar to network diagram
• Measures of effectiveness
• Balance delay ( of idle time)
• Efficiency

12
Layout Types

• Fixed-Position
• Process or Functional
• Product
• Cellular
• Mixed

13
Fixed-Position

• Product is in a fixed position (e.g., airframe,
  ship, building, highway, etc.)
• Resources (people, machines, material) come to
  the product
• Requires complex scheduling of resources
• High space requirements to accommodate resource
  movement
• Usually associated with the Project environment

14
Process or Functional

• Groups similar resources together by the function
  or process performed
• Machine examples are milling machines, lathes,
  routers, grinders
• People examples are Invoicing, Accounts Payable,
  Payroll Processing
• Many crossed paths, high space requirements
• Easy to supervise, train, etc.
• Usually associated with the Job and sometimes the
  Batch environments

15
Product

• Resources are arranged to follow the flow of the
  product
• Examples are auto assembly, steel production,
  bottling, etc.
• Often called production lines or assembly lines
• May be straight line, U-shaped, snake
• Provides for very little WIP storage
• Usually associated with Repetitive and Continuous
  Flow environments

16
Cellular

• Resources (labor and equipment) arranged in small
  groups (cells)
• Have responsibility for output, quality,
  maintenance, etc. for a grouping of tasks or
  parts
• Referred to as teams in services sector
• Teamwork essential
• May be straight line or U-shaped no WIP storage
• Most recently developed layout
• Usually associated with Repetitive environment

17
Mixed

• Two or more layout types in 1 facility
• Examples
• Manufacturing burn-in or baking
• Restaurants (kitchen is functional, buffet line
  is product, menu ordering is fixed-position)
• More difficult to plan
• More costly to equip
• More troublesome to maintain

18
U-Shaped Advantages

• Staff flexibility and balance
• Teamwork
• Immediate rework
• Accessibility
• Work and tool distribution
• Linking with other U-shaped layouts