Many process activities in the real world do not complete their processing in a fixed amount of time, but rather vary somewhat from one instance to the next. To simulate this variation, we will use the static process times as a basis for the new distributions we will use for activity times.
In the activities dialog (right-click on activity and choose Properties) change the activity times from the constants to the distributions shown below:
Activity Name |
Properties to Modify |
| Op 10 Clean and Prep |
Time Duration: N(35,5) |
| Op 20 Vacuum Bake | No Change |
| Op 30 Install PCB |
Time Duration: N(40,5) |
| Op 40 Inspect and Test |
Logic: Open logic builder and double click on the WAIT 25 line of logic. In the WAIT dialog, change the value to WAIT N(25,3), by clicking on the "..." button under Value the column, and selecting Distribution. In the distribution builder, select the Normal distribution and enter the mean and standard deviation as 25 and 3 respectively. For more information on using the distribution builder, press F1 while using the distribution Builder. |
| Op 45 Rework | Time Duration: T(60,90,180) |
| Op 50 Record Unit Statistics | Time Duration: U(5,1) |
You may type the distributions directly into the Time Duration field, or use the distribution builder to enter syntactically correct distributions.
Please Note: Microsoft Windows operating systems other that English may use different separator styles for distributions. For example the English OS uses a comma separator as in N(35,5), while a German OS uses a semi-colon as in N(35;5). Process Simulator will use the correct separator for your OS when you use the Distribution Builder to enter distributions; however, if you enter distributions manually, you must use the correct separator based on your OS settings.