Maturity

As a quality attribute, maturity is the degree to which a system, product, or component meets its needs for reliability under normal operation. In other words, how consistently it performs its specified functions without failing, once the usual early-life defects have been found and fixed.

ISO/IEC 25010 classifies maturity as a sub-characteristic of reliability, alongside availability, fault tolerance, and recoverability. Where those three describe how a system copes with, and bounces back from, failure, maturity describes the more basic property of how rarely it fails in the first place under expected conditions. A mature system has already had its obvious defects shaken out through use.

The term is distinct from a capability maturity model, which measures the maturity of an organization’s processes, rather than that of a running system’s behavior.