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• Objectives of designing product Layouts/ Line Balancing/ Designing Process Layouts

  • Solve simple line-balancing problems
  • Develop simple process and product lay outs
• process of assigning tasks to workstations in such a way that the workstations have approximately equal time requirements

  Line balancing
• Goals of Line Balancing:

  • This minimizes the idle time along the line and results in a high utilization of labor and equipment
  • lines that are perfectly balanced will have a smooth flow of work as activities along the line are synchronized to achieve maximum utilization of labor equipment
• Major obstacles to attaining a perfectly balanced line

  • It may not be feasible to combine certain activities into the same bundle, either because of differences in equipment requirements or because the activities are not compatible
  • Differences among elemental task lengths cannot always be overcome by grouping tasks
  • The required technological sequence ma prohibit otherwise desirable task combinations
• is the maximum time allowed at each workstation to complete its set of tasks on a unit

  cycle time
• • Maximum cycle time is given by the summation of the task times
  • Minimum cycle time is given by the longest of the task times
• • The minimum cycle time would apply if there were five workstations
  • The maximum cycle time would apply if all tasks were performed at a single workstation
• As a general rule, the cycle time is determined by the desired output. If the cycle time does not fall between the maximum and minimum bounds, the desired output rate must be revised
• A very useful tool in line balancing is a precedence diagram
• Determining the maximum output

  A) OT / CT

  B) CT / D

  
• a very useful tool in line balancing is a precedence diagram. A diagram that shows elemental tasks and their precedence requirements
• tool used in line balancing to display elemental as and sequence requirements

  precedence diargram
• fill the boxes

  A) CT

  B) Sum of task time

  C) sum of task time

  
• there is another rule called the order of greatest positional weight
• how do you calculate the percent idle time?

  Idle time over the number of workstations times cycle time, then multiply to 100%
• three basic steps of designing process layout

  1. Gather information
  2. Develop a block plan
  3. Design a detailed lay-out
• Step 1. Gather information

  • Space requirements by center
  • Available space
  • Closeness ratings
  • A REL chart( REL is short for relationship)
  • other considerations
• Space Requirements

  • itemizes the specific equipment and space needed for each center, then adds enough circulation space to provide for aisles and the like.
  • Circulation space may consume at least 25 percent of the center's total space
• Available space

  • a block plan is a rough space allocation for each department and indicates its placement
  • the plan need only provide the facility's dimensions and space allocation
• Closeness Ratings

  • the layout designer must also know which centers need to be located close to one another
  • From-to matrix or a REL chart provides the needed information--this matrix gives the number of trips between each pair of departments