Failure Analysis in Subsystem Design for Space Missions

In order for the Function-Failure Design method to be applicable to modern conceptual design, the method needs to be extended from the mechanical domain to include the electrical domain as very few modern systems are purely mechanical in nature. Towards this goal, we supplement previous efforts describing a standardized vocabulary for mechanical failures by presenting the current state of an electrical and a mechanical failure mode taxonomy. Failure is defined in terms of the cause of the failure mode, the failure mode, and the effect of the failure mode that renders a mechanical, electrical, or electromechanical device incapable of satisfactorily performing its intended function under normal usage conditions. We utilize an elemental physics of failure approach to define failure mode and then use this definition and a variety of resources to develop the electrical failure modes presented in the taxonomy. The list of proposed electrical failure modes is tested against a set of NASA problem reports before being revised to include additional failure modes encountered in space applications. The resulting taxonomy is summarized in the form of 38 electrical failure modes organized into 13 categories. The final version of the mechanical and electrical failure mode taxonomy will be combined with a functional modeling approach to predict potential failures during the conceptual stages of design.