Analysis of alternative rework strategies for printed wiring assembly manufacturing systems

The authors present a model for predicting the cost of test, diagnosis, and rework activities in the manufacture of printed wiring assemblies (PWAs). Two alternative rework strategies for contemporary PWA manufacturing systems are presented: terminal rework and distributed network. The authors analyze the economic basis for deciding between the two rework strategies. The authors assume that the only reason for utilizing distributed rework is to reduce the cost of producing acceptable PWAs, otherwise the cost of the distributed rework effort cannot be justified. The authors present a model of each rework strategy. The effect of each strategy on first-pass yield (FPY) of the manufacturing process is discussed. The effect on FPY is then used to evaluate the economic benefit of each rework strategy as an aid in deciding which strategy to use. The increase in FPY needed to justify distributed rework is calculated