In some cases, the failure analysis team finds that all components meet their requirements, the system was properly assembled, and it was not operated or tested in an out-of-specification manner, yet it still failed. When this occurs, the only conclusion the failure analysis team can reach is that it missed something in its analysis or that the design is defective. This chapter focuses on the latter possibility by discussing the various factors that a failure analysis team should consider to identify the causes of defects in system design. These include requirements identification and verification, circuit performance, mechanical failures, materials...