Benefits of Simulation

I recently had a discussion with a scheduler at a manufacturing plant. I was trying to explain to him the benefits of simulation, and I thought it might be a good discussion to post here as well.

First, here is a brief, although certainly not all-inclusive, list of the key benefits of simulation:

• Answer Questions
• Identify Problems
• Animation & Visualization
• Communication
• Understanding

I am sure you are well aware of these benefits and others. But I want to take a moment and focus on the one I think is most important – Understanding. There are two aspects of this I want to elaborate on.

First, the process of modeling provides the model builder an in-depth look at the existing system. When someone takes the time to build a simulation model, it is much more involved than building a flowchart. A simulation model should be a close representation of the system. The results of the model must validate with reality, which is something you can’t do with a flowchart. The act of building a representative model drives the modeler to understand the flow, the routing logic, the priorities, the resource constraints, and the decisions made on the plant floor!  The modeler must spend time understanding the day to day operational decisions made on the shop floor which goes far beyond the effort one would ever put into a flowchart or a value stream map.

The second aspect is more interesting. Many system experts might have an understanding of their existing system on the surface, but they don’t understand the “physics” of it. Let me explain. The scheduler I mentioned earlier completely understood his current factory. However, if the scheduler were to change the rules he applied, and/or change the job priority scheme at various processes, and/or reduce or increase the batch size, and/or reduce or increase the total Work In Process, and/or change any other major aspect of the system – then neither the scheduler nor anyone else in the plant would be able to predict the effects!

However, think of what would happen if you gave the plant scheduler a simulation model. He could experiment with the model and fairly accurately predict what would happen with policy changes like the ones previously mentioned.  With this toolset, the scheduler could experiment with various policy changes to see what would affect the system in the most positive way and could radically improve the system.  Using simulation, all of the disruptive testing of these policies would be done in the model and NOT on the plant floor. The plant scheduler could really become the Yoda of the plant.