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.