Defining Assumptions

  To define an assumption:

1. Review About Assumptions and Probability Distributions.

2. Determine the most appropriate probability distribution for each uncertain variable:

   • List everything you know about the conditions surrounding this variable.

   • Review the descriptions of the probability distributions in Selecting Probability Distributions.

   • Consider using Crystal Ball’s distribution fitting feature, described in Fitting Distributions to Historical Data.

   • Select the distribution that characterizes the variable.

3. Enter the assumption as described in the next section, Entering Assumptions.