Qualtech Systems, Inc. (QSI) in collaboration with Dr. Stephen B. Johnson of Dependable Systems Technologies (DST) proposes a novel, causal graph-based model and a systematic modeling methodology for assessing damage propagation due to one or multiple originating faults and how the propagation affects and damages other components. In fault propagation, downstream components from the root-cause fault which rely on its function, may also fail. When the root cause is mitigated, those downstream components resume their normal operating behavior. During damage propagation, the originating faults damage, leads to the failure effects in which physical damage to downstream components is a consequence, such that those components can no longer function nominally. Even if the originating fault recovers or is replaced or bypassed, the downstream damaged components do not recover and continue to remain in a failed state. This proposal aims to create a new software module for QSIs TEAMS® tool suite that incorporates component damage as a failure cause and can identify the differences between components in which failure effects pass through or cause only functional impairment versus those that can cause physical damage. This new capability will enable the modeler to represent damage induced component failure modes and their interaction with functional failure modes. Distinction between the two, where the functional failure mode can be caused by damage or bad inputs from impairments upstream, will allow TEAMS® to generate a more comprehensive and accurate assessment of the health of the components of the system and facilitate appropriate mitigation actions. Anticipated
Benefits: The proposed technology is aimed at facilitating effective usage of model-based systems engineering for improving fault tolerance and mitigation response capability during design, and the concomitant software tool for supporting its implementation, will allow NASA to better design, plan and execute future Science Missions. The proposed technology is positioned for direct applications for NASA missions that deploy complex equipment such as the Lunar Gateway, the Space Launch System, the Human Lander, Europa Clipper and rovers such as the VIPER. We envisage the proposed technology to be of significant interest for DoDs Mission planning and Rapid design of space missions/satellites where model-based design processes will be used for supporting infrastructure Space services capabilities. QSI is currently working with the Army for fault management design of the Remote Combat Vehicle (RCV) and plan to apply this technology for that effort.