Definition(s)
Reliability
Ability of a component or system to perform its required function without failure during a specified time interval routine personnel transfer everyday routine personnel transfer, without specific supporting documentation (i.e. DNV GL approved personnel transfer procedure)
Source: Offshore Gangways, DNVGL-ST-0358, DNV GL, September 2017. Global Standards
Reliability
Ability of an item to perform a required function under given conditions for a given time interval.
Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards
Source: Rules for Classification and Construction, IV Industrial Services, 6 Offshore Technology, 9 Guideline for Personnel Transfers by Means of Lifting Appliances, Edition 2011, Germanischer Lloyd SE, Global Standards
Reliability
The ability of a component or a system to perform its required function under given conditions for a given time interval.
Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global Standards
Reliability
Indicator of the extent to which examination scores are consistent across different examination times and locations, different examination forms and different examiners
[SOURCE: ISO/IEC 17024:2012, 3.18].
Source: ISO/IEC TS 17027:2014, Conformity assessment – Vocabulary related to competence of persons used for certification of persons, Global Standards
Reliability
Property of consistent intended behaviour and results.
Source: ISO/IEC 27000:2014, Information technology — Security techniques — Information security management systems — Overview and vocabulary, Third Edition, January 2014. Global Standards
Reliability 3.1.8
R(t)
〈measure〉 probability for an item to perform a required function under given conditions over a given
time interval
z S m =
−
Note 1 to entry: This is a time-dependent parameter.
Note 2 to entry: This parameter is related on a continuous functioning from 0 to t.
Note 3 to entry: For non-repairable items, Reliability and Availability are identical
Note 4 to entry: In IEC 60500–191[14], the reliability is defined both as ability and as measure.
Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards
Reliability
Ability of a structure or a structural component to fulfill the specified requirements.
Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global Standards
Reliability
The ability of a component or a system to perform its required function without failure during a specified time interval.
Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global Standards
Reliability
Proportion of occasions a barrier or equipment item will function as designed (%).
Source: OGP Report No. 415, Asset integrity – the key to managing major incident risks, International Association of Oil & Gas Producers, December 2008. Global Standards
Reliability
Ability of an item to perform a required function under given conditions for a given time interval.
- NOTE: 1 The term “reliability” is also used as a measure of reliability performance and may also be expressed as a probability.
Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global Standards
Reliability
Ability of a system to perform a required function under stated conditions for a specified period of time.
Source: ANSI/ISA–99.00.01–2007, Security for Industrial Automation and Control Systems, Part 1: Terminology, Concepts, and Models, 29 October 2007. National Standard
Reliability
Ability of an item to perform a required function under given conditions for a given time interval.
- NOTE: 1 The term “reliability” is also used as a measure of reliability performance and can also be defined as a probability.
- NOTE: 2 For more detailed definitions and interpretations, see Annex C.
Note that the definition of availability given in IEC 60050-191:1990, 3.1.1, can be misleading because it can lead one to think that “availability” and “reliability” are the same concepts. This is not true because the meaning of “over a given time interval” is not at all the same for the concepts of “availability” and “reliability”. Even if the definitions of “availability” and “reliability” seem very close, these concepts are completely different, specifically: availability: item working at a given instant (no matter what has happened before); reliability: item working continuously over a whole period of time. “Availability” characterizes a function that can be interrupted without any problem and “reliability,” a function that cannot be interrupted over a whole period of time.
Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards