Tip #002 - Concurrent Processing index

If you have a process that has a large group of machines that do the same thing it might be advantageous to model this group as one element in your model. This way you can simplify your model and get one set of results that represent the entire group of machines. There are two ways of tackling this situation. Both ways have pros and cons.

Method 1

  1. Create a buffer with large capacity.
  2. Trigger on entry => att1[C]:=time+negexp[50]
  3. Queue discipline => min att1
  4. Exit condition => time>att1[E,1]

Pros: Accurate if screen refresh is set at every 1 unit.
Cons: Slow and utilisation is not recorded.

Method 2

  1. Create a machine with a large capacity
  2. Trigger on entry => att1[C]:=time+negexp[50]
  3. Queue discipline => min att1
  4. Time => if att1[E,1]-time<0 then 0 else att1[E,1]-time

Pros: Fast, doesn’t depend on refresh rate and utilisation is recorded.
Cons: Some inaccuracies due to the fact that a processed part will not be included in the queue sortation.