Failure

Failure is any fault, defect, or error that impairs a service or product from meeting the customer needs.

Definition

According to Juran's Quality Handbook by Defeo (7th edition),

Failure. Any fault, defect, or error that impairs a service or product from meeting the customer needs.

According to the INCOSE Systems Engineering Handbook (4th edition),

Failure. The event in which any part of an item does not perform as required by its specification. The failure may occur at a value in excess of the minimum required in the specification, that is, past design limits or beyond the margin of safety.