Goal Seek

The Goal Seek tool is used to find the value of one tree node required to set a dependent node to a specific value including its maximum or minimum. For example, Goal Seek will find the value of Sales required for Profit to break even (be equal to zero). DecisionPro will modify the input node's definition to reflect the solution found.

To find the value of an input node required to achieve a desired result on an output node:

1) In the Tools menu, click Goal Seek.

2) Enter the name of the output node in the Set node field.

3) Choose value in the equal to field and enter the target result.

4) Enter the name of the input node in the by changing field.

5) Click OK.

The accuracy of the solution is determined by the precision setting.

Goal Seek uses the current value of the input node as a starting point for finding a solution. If Goal Seek is unable to find a solution, change the input node's value to one that is closer to producing the desired result.

Rather than find the value of an input required to set an output to a specific value, you can find the value required to set the output to a maximum or minimum value. To do this, simply choose maximum or minimum in the equal to field.

In order for Goal Seek to find a maximum, the output node's value, when plotted over a range of values for the input node, must be cupped downward. Similarly, to find a minimum the curve must be cupped upward. If the relation between the input and output nodes is linear, no maximum or minimum exists.

Goal Seek uses the root and minimize primitives to calculate a solution. See the online help system for more information about these functions.