Formulas for the Bench Operation Process
See also Stretch Forming Tooling.
Cycle Time = Process Time * Cycle Time Adjustment Factor
Cycle time is the product of the following:
• Process time: unadjusted cycle time for the current process. See the formula below.
• Cycle Time Adjustment Factor: value of the cost model variable cycleTimeAdjustmentFactor. This is set to 1 in aPriori starting point VPEs. VPE administrators can change the cost model variable to globally adjust cycle times.
Process Time = Handling Time + Manual Clean Time + Inspecting Time +
Manual Forming Time
Process time is the sum of the following:
• Handling time: this includes loading and unloading time. Both are looked up by stock mass in the lookup table tblMaterialHandling.
• Manual clean time: this is the time required to clean the formed part. It is looked up by blank area in the lookup table tblStretchForm, and bounded below by the cost model variable minimmManualCleanTime (10 seconds in starting point VPEs). Blank area includes the surface area of both sides of the blank—it is twice the product of the blank’s length and width.
• Inspecting time: this is the time to inspect the formed part. By default, it is specified by the cost model variable defaultFinalInspectionTime (5 minutes in starting point VPEs). Users can override the default with the setup option Final Inspection Time.
• Manual Forming time: this is the sum of the cycle times for the Manual Forming operations. The time for each form on which this operation is performed is the length of the form divided by the value of the cost model variable defaultManualFormFormingRate (50mm/minute in starting point VPEs).
Expendable Tooling Cost
This is the cost for wet wipes used to clean the formed part. The cost model assumes the use of one wet wipe for every 4 meters of blank area. Blank area includes the surface area of both sides of the blank—it is twice the product of the blank’s length and width. The model assumes that at least one wet wipe is used, and that a whole number of wet wipes is used. The cost per wet wipe is specified by the tool shop variable consumableMaterial_CleaningWipes.