Time changes due to the variable nature of the entity or activity or as a result of the inconsistent behavior of the resource used at the activity.
1. Determine the probability distribution that best fits the activity time (more on probability distributions).
2. Enter the probability distribution in the Time field of the General properties sheet for the activity (alternatively, a TIME statement can be used in the action logic for the activity).
Example: A phone-in order may have a time that is triangularly distributed with a minimum of 2 minutes, a mode of 5 minutes, and a maximum of 12 minutes
TO DO: In the Time field of the General properties dialog enter T(2, 5, 12) as shown above. Alternatively, you could enter Action Logic for the activity: TIME T(2, 5, 12) Min.