Factory Explorer® Technical Alert #27
For All Users of Factory Explorer® v2.7

Calculation of Predicted Percent Rework when using
Hold Tool, Free After This Step


Summary: When using the Hold Tool, Free After This Step (FREESTEP) column in the Process worksheet, the Top Bottleneck Resources chart displays the predicted hold time incorrectly as Percent Rework. This should be included as Percent Non-Rework and occurs even when there is no rework in the model.

Details: When using the Hold Tool, Free After This Step (FREESTEP) column in the Process worksheet, Factory Explorer®'s capacity analysis engine calculates the Total Predicted Percent Work (which includes an estimate for how long the tool will be held). Then, it calculates Predicted Percent Non-Rework (e.g. what percent of time it will spend processing non-rework units, which DOES NOT include the hold time estimate). After that, it calculates Predicted Percent Work = Percent Work (Total) - Percent Non-Rework. So, by default, the predicted hold time gets lumped into the rework value. Hence, the Top Bottleneck Chart includes an estimate of hold time in the Predicted Percent Rework column.

Workaround: When the Hold Tool, Free After This Step (FREESTEP) feature is used and there is no rework in the model for tool groups that are held, add the Predicted Percent Rework column to the Predicted Percent Non-Rework column, and zero out the Predicted Percent Rework column for these tool groups.

This bug will be corrected in the next release of Factory Explorer®.

Techalert tafx27-0006


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