Process Simulation

How to detect problems in the design

Detecting ‘process flaws’ by simulating the process

A well designed process is executed correctly under all circumstances (full-proof and fool-proof). Furthermore, a correct process does not have unnecessary steps. This seems trivial but in practice this is not easy. To test a design, a process simulation with the use of PSD’s can be very helpful.

Have a look at the following example:

At first sight this procedure looks correct. However, there are three mistakes in this procedure:

Mistake 1

The first action is to open the book. Then we need to assess if the page number is unequal to the last page number. We cannot give an answer to this question, because we have no information about the last page number! Furthermore, we do not know on which page we opened the book.

Mistake 2

What happens when we turn over the last but one page and arrive at the last page? Then the page number is equal to the last page number. At this point the condition is no longer satisfied and the last page is not read.

Mistake 3

The situation at the start of the process is unknown. So opening the book, the first action, is at random.

Benefits of simulation

A PSD gives the opportunity to simulate a process during the design phase. Gaps are identified easily because of the visualized process. This prevents mistakes after implementation during execution. Both structural and sporadic mistakes are traced using the PSD simulation in an early stage.

Below the example is corrected:


The next step is to analyse if the correct PSD for *** reading a book *** can be optimized. Can we eliminate unnecessary actions? An option is to read the book without constantly paying attention to the page number.

Advantages of Process Simulation

The process simulation prevents bothering your organization with trial and errors. You may first design the needed workflow. What decisions that have to be made? And where are the go-no go points? Only then you can start thinking about how- and by whom those actions and decision need to be taken.

If the design of the process is full-proof in the process simulation, the design will become your bacon to steer upon when implementing it in your organization.

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