Rivet Process Formulas
Rivet Time = (Labor Time / Number of Operators) * Cycle Time Adjustment Factor
Cycle time depends on the following:
• Labor time (see formula)
• Number of operators (specified by the machine property Number of Operators).
• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs. If you want to model an unbalanced, push assembly line, set cycleTimeAdjustmentFactor to a value greater than 1 in order to account for the cost of extra buffer capacity.
Labor Time = Rivet Time + Rivet Extra Time
Labor time is the sum of the following:
• Rivet time (see formula)
• Rivet extra time (see formula)
Rivet Time = Rivet Time per Hole * Number of Riveted Holes
Rivet time is the sum of the following:
• Rivet time per hole: this is the time to rivet one hole, in the absence of obstructions or vision difficulties. It is looked up by process group ('Assembly') and process name ('Rivet') in the lookup table tblMechanicalOperationTimes (3 seconds in starting point VPEs).
• Number of riveted holes (see formula)
Rivet Extra Time = Rivet Extra Time per Hole * Number of Riveted Holes
• Rivet extra time per hole: this accounts for any extra time required to rivet the hole due to an obstruction or vision problem. The extra time is looked up in the lookup table tblMechanicalOperationTimes by the following:
o Process group name ('Assembly')
o Process name ('Rivet')
o Setting of the PSO Rivet Obstructed Or Vision.
The extra time is 0 if the PSO setting is No obstructed access or vision problem (the default in starting point VPEs).
• Number of riveted holes (see formula)
Number of Riveted Holes =
Number of Riveted Simple Holes + Number of Riveted Complex Holes
By default, the number of riveted holes is the sum of the following:
• Number of riveted simple holes: this is the number of SimpleHole GCDs whose diameter is within range (see below).
• Number of riveted complex holes: this is the number of ComplexHole GCDs whose MEC diameter (diameter of the largest circle that fits inside the hole) is in range.
A diameter or MEC diameter is in range if it is between the values of the following cost model variables:
• minRivetDiameter (2mm in starting point VPEs)
• maxRivetDiameter (8mm in starting point VPEs)
Users can override the default number of holes with the setup option Riveted Hole Count.