Crystal Ball uses three types of data cells as inputs and outputs:
Assumption cells are input cells that contain values that you are unsure of: the uncertain independent variables in the problem you are trying to solve. The assumption cells must contain simple numeric values, not formulas or text.
Decision variable cells are input cells that contain values that are within the control to change. The decision variable cells must contain simple numeric values, not formulas or text. These are used by some of the Crystal Ball tools and by OptQuest.
Forecast cells (dependent variables) are output cells that contain formulas that refer to one or more assumption and decision variable cells. The forecast cells combine the values in the assumption, decision variable, and other cells to calculate a result. A forecast cell, for example, might contain the formula =C17*C20*C21.