How aPriori adjusts cycle times based on tolerances

For a given GCD and process, aPriori adjusts cycle times by a compensation factor that is based on:

• Tolerances that you specify or import for the GCD

• Tolerance ranges for the process and the GCD (see How aPriori calculates achievable tolerance ranges)

• Compensation factor ranges specified by plant.gtolWorstAchievableFactor (0.75 in the starting point Digital Factories) and plant.gtolBestAchievableFactor (1.5 in the starting point Digital Factories).

The position of the specified tolerance within the tolerance range determines the position of the compensation factor within the compensation factor range such that:

• If the tolerance specified for a GCD is at the midpoint of the tolerance range, then the compensation factor is 1.

• If the tolerance specified is in the bottom half of the tolerance range, the compensation factor is between plant.gtolWorstAchievableFactor and 1.

  Specifically, if the tolerance specified is a certain fraction of the way from the worst achievable tolerance to the midpoint of the tolerance range, the compensation factor is that same fraction of the way from plant.gtolWorstAchievableFactor to 1.

• If the tolerance specified is in the top half of the tolerance range, the compensation factor is between 1 and plant.gtolBestAchievableFactor.

  Specifically, if thetolerance specified is a certain fraction of the way from the midpoint of the tolerance range to the best achievable tolerance, the compensation factor is that same fraction of the way from 1 to    plant.gtolBestAchievableFactor.

• If no tolerance has been specified for a GCD, the compensation factor is 1.