1. Network management functions extended to include subscriber elements or user end instruments.
2. In computer systems, synonym system administration.

The person ultimately responsible for the production and enforcement of a System Security Policy [CESG]. See also: System Administrator, System Security Officer.

For a supported performance parameter of a system, the value that establishes the minimum operational service performance level for the parameter.
Note: A measured parameter value worse than the system operational threshold indicates that the system is in an outage state.

See overhead information.

Synonym power margin.

[In INFOSEC, the] detailed security description of the physical structure, equipment component, location, relationships, and general operating environment of an information system (IS). [INFOSEC-99]

The probability that a system, including all hardware, firmware, and software, will satisfactorily perform the task for which it was designed or intended, for a specified time and in a specified environment. [From Weik '89]

The measure or extent of the ability of a system, such as a computer, communications, data processing, or weapons system, to continue to function despite the existence of faults in its component subsystems or parts.
Note: System performance may be diminished or otherwise altered until the faults are corrected.

[In INFOSEC, the] degree of security as determined by evaluation of the totality of all system elements and INFOSEC countermeasures. [INFOSEC-99]

The effort to achieve and maintain optimal security and survivability of a system throughout its life cycle. [INFOSEC-99]