Defect, Degradation and Failure

What this topic covers

Distinguish an observed indication from loss of required function.

Core ideas

An indication is something detected by an inspection or monitoring method.

A defect is an imperfection that may need engineering assessment depending on service and acceptance criteria.

A failure occurs when required function is lost; not every detected indication means failure is imminent.

Program tradeoffs

A mature program does not inspect everything equally; it identifies credible degradation and prioritizes the assets where loss of function matters most.

What good evidence looks like

Data quality, asset identity and decision ownership are as important as the sensor or inspection method.

Lifecycle perspective

Lifecycle thinking links design, operation, maintenance, renewal and retirement rather than treating integrity as a late-life activity.