Using Probability Functions

For each of the Crystal Ball distributions, there is an equivalent Microsoft Excel function. You can enter these functions in the spreadsheet directly instead of defining distributions using the Define Assumption command. Be aware, though, that there are a number of limitations in using these functions. For details, see Limitations of Probability Functions.

Also see Probability Functions and Random Seeds for information about setting a random seed so probability functions can have comparable values.

To view these functions and their parameters, choose Insert, then Function in Microsoft Excel, and then be sure the category is set to Crystal Ball (Figure 131, Crystal Ball Functions in Microsoft Excel, following).

(In Microsoft Excel 2007 or later, choose Formulas, then Insert Function.)

Figure 131. Crystal Ball Functions in Microsoft Excel

This figure displays Crystal Ball functions in Microsoft Excel.

Parameters and a brief description are displayed below the list of functions. The Cutoff parameters indicate truncation values, while NameOf is the assumption name. For parameter descriptions and details on each distribution, see the entry for that distribution earlier in this appendix.

Note:

The beta distribution is now different from versions earlier than Crystal Ball 7.0. Both the original and revised functions are displayed for compatibility. CB.Beta has three parameters but CB.Beta2 is the current Crystal Ball version with Minimum and Maximum instead of Scale.