mo. facilities

Capacity and Facilities Planning

Roberta Russell & Bernard W. Taylor, III

      Capacity Planning

      Basic Layouts

      Designing Process Layouts

      Designing Service Layouts

      Designing Product Layouts

      Hybrid Layouts

Facility Layout

Arrangement of areas within a facility to:

Ø Minimize material-handling costs

Ø Utilize space efficiently

Ø Utilize labor efficiently

Ø Eliminate bottlenecks

Ø Facilitate communication and interaction

Ø Reduce manufacturing cycle time

Ø Reduce customer service time

Ø Eliminate wasted or redundant movement

Ø Increase capacity

Ø Facilitate  entry, exit, and placement of material, products, and people

Ø Incorporate safety and security measures

Ø Promote product and service quality

Ø Encourage proper maintenance activities

Ø Provide a visual control of activities

Ø Provide flexibility to adapt to changing conditions

BASIC LAYOUTS

w  Process layouts

n  group similar activities together according to process or function they perform

w  Product layouts

n  arrange activities in line according to  sequence of operations for a particular product or service

w  Fixed-position layouts

n  are used for projects in which  product cannot be moved

Fixed-Position Layouts

• Typical of projects
• Equipment, workers, materials, other resources brought to the site
• Highly skilled labor
• Often low fixed
• Typically high variable costs

Designing Process Layouts

• Goal: minimize material handling costs
• Block Diagramming
• minimize nonadjacent loads
• use when quantitative data is available
• Relationship Diagramming
• based on location preference between areas
• use when quantitative data is not available

Block Diagramming

w  Unit load

n   quantity in which material is normally moved

w  Nonadjacent load

n  distance farther than the next block

w  STEPS

n  create load summary chart

n  calculate composite (two way) movements

n  develop trial layouts minimizing number of nonadjacent loads

Computerized layout Solutions

w  CRAFT

n  Computerized Relative Allocation of Facilities Technique

w  CORELAP

n  Computerized Relationship Layout Planning

w  PROMODEL and EXTEND

n  visual feedback

n  allow user to quickly test a variety of scenarios

w  Three-D modeling and CAD

n  integrated layout analysis

n  available in VisFactory and similar software

Designing Service Layouts

w  Must be both attractive and functional

w  Types

n  Free flow layouts

l  encourage browsing, increase impulse purchasing, are flexible and visually appealing

n  Grid layouts

l  encourage customer familiarity, are low cost, easy to clean and secure, and good for repeat customers

n  Loop  and Spine layouts

l  both increase customer sightlines and exposure to products, while encouraging  customer to circulate through the entire store

Designing Product Layouts

w  Objective

n  Balance the assembly line

w  Line balancing

n  tries to equalize the amount of work at each workstation

w  Precedence requirements

n  physical restrictions on the order in which operations are performed

w  Cycle time

n   maximum amount of time a product is allowed to spend at each workstation

Line Balancing Procedure

1. Draw and label a precedence diagram
2. Calculate  desired cycle time required for the line
3. Calculate  theoretical minimum number of workstations
4. Group elements into workstations, recognizing cycle time and precedence constraints
5. Calculate  efficiency of the line
6. Determine if the theoretical minimum number of workstations or an acceptable efficiency level has been reached. If not, go back to step 4.

Computerized Line Balancing

• Use heuristics to assign tasks to workstations
• Longest operation time
• Shortest operation time
• Most number of following tasks
• Least number of following tasks
• Ranked positional weight

Hybrids Layouts

w  Cellular layouts

n  group dissimilar machines into work centers (called cells) that process families of parts with similar shapes or processing requirements

w  Flexible manufacturing system

n  automated machining and material handling systems which can produce an enormous variety of items

w  Mixed-model assembly line

n  processes more than one product model in one line