A new test/diagnosis/rework model for use in technical cost modeling of electronic systems assembly

This paper presents a test/diagnosis/rework analysis model for use in technical cost modeling of electronic assemblies. The approach includes a model of test operations characterized by fault coverage, false positives, and defects introduced in test, in addition to rework and diagnosis operations that have variable success rates and their own defect introduction mechanisms. The model can accommodate an arbitrary number of rework attempts on any given assembly and can be used to optimize the fault coverage and rework investment during system tradeoff analyses. The model's implementation allows all inputs to the model to be represented as probability distributions thereby accommodating inevitable uncertainties in input data present during tradeoff activities and uses Monte Carlo methods to determine model outputs.

I. Introduction

At a fundamental level, electronic system design is a tradeoff analysis activity with uricertain inputs. This tradeoff includes factors such as size and performance, but often the most important factor in the tradeoff is cost. The various costs that affect the manufacture of the system are the fabrication or assembly cost, test/inspection cost, rework cost, and waste disposition cost. In addition, there are significant nonmanufacturing life cycle costs associated with system sustainment, end-of-life, and other issues. Of the manufacturing costs, the test and the rework costs can be very important drivers that significantly affect the total cost of manufacturing for many products. Modeling the test/diagnosis/rework costs accurately may determine the extent to which the system designer can control and optimize the manufacturing cost.