Applies to:
@RISK 5.x and Up

 

Shoeprint (Iteration Step) Mode Shows Different Values or Numbers Instead of Errors

Issue:
When running a simulation, some outputs may show errors. Opening the Data Window, selecting an iteration with errors, and clicking the Shoeprint (Footprint) Mode icon can result in:

• A number appearing in the worksheet where an error was shown in the Data Window.

• Different numbers in the worksheet compared to the simulation results.

Explanation:
When you enter Shoeprint mode, @RISK places all input values for that iteration into the workbook. However, it does not directly set output values. Instead, Excel recalculates the workbook, which fills in the output cells.

Because of this, @RISK outputs may differ from the original simulation if:

• The workbook logic was modified after the simulation ran.

• The workbook contains features that make the simulation non-reproducible.

For more information, see: Reproducibility in @RISK: Random Number Generation, Seed Values, and Reproducibility.

Common Scenario – Conditional Logic in Inputs:
If an input cell contains a formula with conditional logic, e.g.:

=IF(A45="Yes", RiskNormal(250,15), 0)

• @RISK records values of the distribution functions (RiskNormal in this example), not the calculated cell values.

• When the condition is false (A45 ≠ "Yes"), the formula evaluates to 0, but the RiskNormal distribution is not evaluated, so @RISK records it as an error.

Key Points:

• An input showing "error" in the simulation does not always indicate a formula error.

• It may reflect that the distribution was not evaluated during that iteration due to the model’s logic.

• In Shoeprint mode, Excel recalculation produces a number in the cell, even if @RISK originally recorded an error.

Summary:
Shoeprint mode places iteration inputs into the workbook and lets Excel recalculate outputs. Differences between simulation results and Shoeprint values usually stem from:

1. Workbook changes after simulation.

2. Non-reproducible model logic.

3. Conditional formulas preventing some distributions from being evaluated.