scope:

This standard specifies and classifies measures of the software aspects of dependability. It is an expansion of the scope of the existing standard; the revision includes the following aspects of dependability: reliability, availability, and maintainability of software. The applicability of this standard is any software system; in particular, it applies to mission critical systems, where high reliability, availability, and maintainability are of utmost importance. These systems include, but are not limited to, systems for military combat, space missions, air traffic control, network operations, stock exchanges, automatic teller machines, and airline reservation systems.