faultdefined

Faultdefined is a term used in engineering to describe a systematic practice of explicitly defining and documenting potential faults within a system and their consequences. It centers on creating a formal fault model, a fault dictionary, and corresponding mitigation strategies, with the aim of improving reliability, safety, and verifiability across the development life cycle.

A typical faultdefined approach involves three elements: a fault model that categorizes faults by type and origin; a fault dictionary or catalog that links each fault to its expected failure modes, effects, and detection opportunities; and a set of recovery or containment procedures designed to prevent fault propagation.

In practice, faultdefined is applied early in the design process and iterated during verification and validation. It is commonly used in safety- and mission-critical domains such as automotive, aerospace, medical devices, and large-scale software systems. The method supports traceability from requirements to testing by clarifying how faults are supposed to be handled.

Benefits include improved hazard analysis, clearer risk ownership, and more targeted testing for fault handling. Critics note that the approach can introduce overhead if the fault catalog is overly broad or poorly maintained, and that its value depends on discipline in maintenance and integration with existing safety practices.

Relation to other concepts: faultdefined shares goals with failure mode and effects analysis, fault tree analysis, and fault-tolerance engineering, but emphasizes an explicit, defined catalog of faults as a core deliverable. It has no universal formal standard, and its adoption varies by organization and sector.