The SIMUL8 Brain

The need for speed – make your simulation faster

Frances Sneddon  /   Sep 26, 2010

SIMUL8 is known for its very fast run times. Independent trials have been shown to be 6 times faster than our nearest speed competitor when running simulations of the same system. Below are some tips to increase the run speed of your simulation.

No Routing Discipline Conflicts

Routing Discipline conflicts can slow down your simulation because SIMUL8 has to do more calculations to decide where the work item should go. To avoid this, make sure your simulation never has a priority routing-out object linking into a priority routing-in object. This can be corrected by placing a storage bin between these items or changing one of the routing disciplines to passive.

High Volume

If you are working with hundreds of thousands of work items that are essentially the same considered using High Volume. Maybe this could even be used for part of your system. This is useful for modeling many items with similar properties. All your work items are batched up and treated in bulk rather than individually so there are lots less events to process.

Results Synchronization Interval

You can change the Results Synchronization Interval using File>Preferences>Results.

The default interval to collect results in SIMUL8 is every five time units. If you require greater accuracy this interval can be reduced, but to increase the speed of your model this interval can also be increased. In simulations that run over a long time period with many events, you can also increase this time interval to save memory, if this is an important factor to you.

Simulation Exit Objects

Information carried on work items often take up a lot of memory, particularly if you have many work items. By ensuring where possible that your simulation exit objects are specific Work Exit Points rather than Storage Bins for example, this will ensure less memory is used recording finished work item’s label values.

Minimum Wait Time and Shelf Life

Storage bins making use of the Minimum Wait Time or Shelf Life features may also impact the speed that your simulation runs. This is due to SIMUL8 having to generate lots of events to keep checking on the status of the work item. You could use a Work Center with replicate set to a high value and the cycle time to represent the wait time instead, then you only have one event per work item.

Simulation Objects that Collect Results

By default every simulation object in SIMUL8 collects results. Turn off results collection for objects you’re not interested in, for example dummy Work Centers added for routing purposes. This saves memory space on the PC and can allows simulations to run faster, reducing the execution time for each run.

Use Results>All and highlight each object you want to switch results collection off (or on) then check or un-check the “Collect Results” check box. You can highlight one or many objects at the same time using Ctrl or Shift keys.

These are just a few ways you can make your simulations even faster. If you’d like more advice please email and one of our consultants would be glad to speak with you.

About the author

Frances Sneddon

Frances Sneddon

As Chief Technology Officer for SIMUL8, I am responsible for the strategy and direction of our products, it's also my passion. I love software and every part of what goes into creating an amazing end user experience from the initial connection with our website, to how you interact with the software itself.