The continued increase in complexity of automotive electronics has further necessitated for systems to be designed for optimal testing and servicing in the field. Locating failures within complex, interactive electronic systems can create conditions of both high warranty costs and customer dissatisfaction. Decisions about levels of system integration and diagnostics early in the design phases are fundamental parts of these considerations and are addressed in this paper.The approach focuses on projecting field repair rates and maintenance costs using a Monte Carlo computer simulation method given various component parameters such as part costs, reliability, labor time, and field diagnostic strategies. Results of the projection technique were shown to be quite accurate in projecting field warranty costs of a complex electronic system. Simulation studies of several vehicle electronic systems show that large reductions in field maintenance costs can be achieved through proper selection of diagnostic strategy and levels of design integration.