References

The public standards, reports and primary documents this topic draws on. Every factual claim in the preceding chapters traces to one of these; the numeric examples (the radar-station table, the nines arithmetic) are illustrative and belong to no source.

Standards and handbooks

1. IEC 60050-192:2015, International Electrotechnical Vocabulary, Part 192: Dependability, International Electrotechnical Commission, February 2015, with Amendment 1, 2016 (the definition of availability at IEV 192-01-23; the availability measures of section 192-08, from instantaneous to steady-state).
2. IEC 61703:2016, Mathematical expressions for reliability, availability, maintainability and maintenance support terms, Edition 2.0, International Electrotechnical Commission, 2016 (the mathematical companion to the IEV vocabulary, including the state-transition and renewal-process models).
3. MIL-STD-721C, Definitions of Terms for Reliability and Maintainability, US Department of Defense, 12 June 1981, since cancelled (the operable-and-committable-at-a-random-time definition of availability and the inherent/achieved/operational vocabulary).
4. MIL-HDBK-338B, Electronic Reliability Design Handbook, US Department of Defense, 1 October 1998 (Section 5.7: instantaneous, mission and steady-state availability with the two-state Markov derivation of A(t); Section 10: the series and parallel availability models and the shared-repair-crew caveat).
5. MIL-HDBK-470A, Designing and Developing Maintainable Products and Systems, Volume I, US Department of Defense, 4 August 1997 (the inherent and operational availability equations and the MTTR-versus-MDT distinction).
6. IEC 61508:2010, Functional safety of electrical/electronic/programmable electronic safety-related systems, Edition 2.0, International Electrotechnical Commission, 2010 (the low-demand-mode average probability of failure on demand for periodically proof-tested safety functions).
7. EN 50126-1:2017, Railway Applications: The Specification and Demonstration of Reliability, Availability, Maintainability and Safety (RAMS), Part 1: Generic RAMS Process, CENELEC, October 2017, with EN 50126-2:2017, Part 2: Systems Approach to Safety (the railway lifecycle frame for RAMS targets).

Primary reports and documents

8. Department of Defense Reliability, Availability, Maintainability, and Cost Rationale Report Manual, Office of the Secretary of Defense, 1 June 2009 (operational availability, materiel availability, and the logistics/administrative delay-time decomposition).
9. PBL Guidebook: A Guide to Developing Performance-Based Logistics Arrangements, US Department of Defense, Release 2023 (the sustainment availability KPP structure and the outcome-based support framing).
10. IAEA Power Reactor Information System (PRIS) glossary, International Atomic Energy Agency (the Energy Availability Factor and Unit Capability Factor definitions; methodology in IAEA Technical Reports Series No. 428).
11. WANO Performance Indicator Programme, World Association of Nuclear Operators (unit capability factor, unplanned capability loss factor, and forced loss rate).
12. Directive (EU) 2018/1972 establishing the European Electronic Communications Code, Articles 108 and 109 (availability of voice services and uninterrupted access to emergency services; the PSAP continuity obligations).

For the two halves of the availability balance, see the Reliability references and the Maintainability references.