Additional line balancing notes

1
Additional line balancing notes

• SOM 306
• Fall 2008
• Abe Feinberg

2
Line Balancing Procedure

• 1. Determine which tasks must be performed to
  complete one unit of a particular product
• 2. Determine the order or sequence in shich the
  tasks must be performed.
• 3. Draw a precedence diagram. This is a flow
  chart where circles represent tasks and
  connecting arrows represent precedence.
• 4. Estimate task times.
• 5. Calculate the cycle time
• 6. Calculate the minimum number of work stations.
• 7. Use one of the heuristics to assign tasks to
  work stations so that the production line is
  balanced.

3
Assembly Line Balancing Formulas

• Cycle time (Available Work Time/ Required
  Output Rate)
• Available Work Time Scheduled Work time
  Breaks
• Theoretical Minimum No. of Stations Total Work
  Required for One Unit/Cycle Time where
  indicates to Next Integer

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Steps 1-2 in the Longest Task Time Heuristic

• 1. Let i1, where I is the number of the work
  station being formed.
• 2. Make a list of all tasks which are candidates
  for assignment to this work station. For a task
  to be on this list, it must satisfy all these
  conditions
• a. It cannot have previously been assigned to
  this or a previous work station.
• b. Its immediate predecessors must have been
  assigned to this or a previous work station
• c. The sum of its task time and all other times
  of tasks already assigned to the work station
  must be lt cycle time. If no candidates can be
  found, go to step 4.

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Steps 3-4 in the Longest Task Time Heuristic

• 3. Assign the task from the list with the longest
  task time to the work station.
• 4. Close the assignment of tasks to work station
  1. This can occur in two ways. If there are no
  tasks on the candidate list for the work station,
  but there are still tasks to be assigned, set
  ii1 and go to step 2. If there are no more
  unassigned tasks, the procedure is complete.