Creation of a new entity occurs only under certain conditions. You can control whether or not an entity is created or the quantity of created entities to suit changing conditions.
Suggested Technique
1. In the create route, replace the quantity created with an attribute, variable, expression or distribution.
Example: A company receives telephone calls, 25 percent of which turn into orders and 75 percent which do not. In either case, calls must be logged and terminated.
TO DO: Place a discrete distribution in the quantity field of the Create routing. See Discrete Distribution.