Visual Inspection Formulas

The Visual Inspection process relies on the formulas below.

Cycle Time = Process Time * Cycle Time Adjustment Factor

Cycle time is the product of the following:

• Process time (see formula below)

• Cycle time adjustment factor: specified by the cost model variable cycleTimeAdjustmentFactor; 1 in aPriori starting point VPEs.

Process Time = (Internal Examination Time + External Examination Time) *

Design Complexity Factor * Core Factor

Process time depends on the following:

• Internal examination time (see formula)

• Design complexity factor (see Design Complexity Factor)

• Core factor. This is a factor that reflects the extra time required for inspection of parts with cored features. For parts with one cored feature, the factor is specified by the cost model variable singleCoreInspectionFactor (1.5 in starting point VPEs); for parts with two or more cored features, the factor is specified by the cost model variable multiCoreInspectionFactor (2 in starting point VPEs).

Internal Examination Time = Internal Inspection Rate * Internal Surface Area

Internal examination time is the product of the following:

• Internal inspection rate: looked up by weight in the lookup table tblVisualInspection.

• Internal surface area. This is the total area of all internal surfaces. Internal surfaces are those for which there is no Normal, Parallel, or Oblique IS_ACCESSIBLE_FROM relation.

External Examination Time = External Inspection Rate * External Surface Area

External examination time is the product of the following:

• External inspection rate: looked up by weight in the lookup table tblVisualInspection.

• External surface area. This is the total area of all external surfaces. External surfaces are those for which there is a Normal, Parallel, or Oblique IS_ACCESSIBLE_FROM relation.