Glossary
Browse the IADC Lexicon alphabetically or by category. Get comprehensive definitions of drilling industry terms.
FMECA
Definition(s)
FMECA
Failure modes effects criticality analysis. Source: API Technical Report 17TR7, Verification and Validation of Subsea Connectors, First Edition, April 2017. Global StandardsFMECA
Failure mode, effects and criticality analysis. Source: ISO 17776:2016, Petroleum and natural gas industries — Offshore production installations — Major accident hazard management during the design of new installations, Second Edition, December 2016. Global Standards Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global Standards Source: Oil & Gas UK, Guidelines on subsea BOP systems, Issue 1, July 2012, Global StandardsFMECA
analysis usually performed after an FMEA (3.21) which can be based on the probability that the failure mode will result in system failure, or the level of risk associated with the failure mode, or a risk’s priority Source: ISO 16530-1:2017, Petroleum and natural gas industries — Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global StandardsFMECA
Failure mode effect and consequence analysis. Source: Rules for Classification – Offshore units, DNVGL-OU-0101, Offshore drilling and support units, DNV GL, July 2015. Global StandardsFMECA
Failure mode, effect and criticality analysis. Source: API RP 17H, Remotely Operated Vehicle (ROV) Interfaces on Subsea Production Systems, First Edition, July 2004 (Reaffirmed January 2009). Global Standards Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards Source: International Association of Drilling Contractors, Appendix 2 to Health, Safety and Environment Case Guidelines for Offshore Drilling Contractors, Issue 3.3.2, February 2010. IADC Guidelines Source: NOPSEMA Guidance note: Hazard Identification, N-04300-GN0107, Australia, Revision 5, December 2012. Regulatory GuidanceFTA
Definition(s)
FTA
Fault-tree analysis. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards Source: ISO 17776:2000, Petroleum and natural gas industries – Offshore production installations – Guidelines on tools and techniques for hazard identification and risk assessment. Global Standards Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsFTA
Fault Tree Analysis. Source: International Association of Drilling Contractors, Appendix 2 to Health, Safety and Environment Case Guidelines for Offshore Drilling Contractors, Issue 3.3.2, February 2010. IADC GuidelinesFTA
Tree-like diagram based upon the application of "and/or'' logic used to identify alternative sequences of hardware faults and human errors that result in system failures or hazardous events. NOTE When quantified, fault trees allow system-failure probability or frequency to be calculated. Source: ISO 17776:2000, Petroleum and natural gas industries – Offshore production installations – Guidelines on tools and techniques for hazard identification and risk assessment. Global StandardsDHSV
Definition(s)
DHSV
Down Hole Safety Valve. Source: Norwegian Oil and Gas Association, Guideline No. 135, Recommended Guidelines for Classification and categorization of well control incidents and well integrity incidents, Rev. 4, 27 June 2017, National or Regional Standards Source: NOGEPA Industrial Guideline No. 41, Well Construction Process Checklist, Drilling Best Practices, Netherlands, Version 0, December 2011. Global StandardsDHSV
Downhole safety valve. Source: 117 OLF, Norwegian Oil and Gas Association recommended guidelines for Well Integrity, No. 117, Revision No. 4, June 2011. Global Standards Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsCMMIS
Definition(s)
CMMIS
Computerized maintenance-management information system. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsCM
Definition(s)
CM
Hydrodynamic inertia coefficient. Source: API Specification 16Q, Design, Selection, Operation, and Maintenance of Marine Drilling Riser Systems, Second Edition, April 2017. Global StandardsCM
Condition monitoring. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsCondition Monitoring
Definition(s)
CM
Condition monitoring. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsCAPEX
Definition(s)
CAPEX
Capital expenditure. Source: API SPEC 17F, Specification for Subsea Production Control Systems, Second Edition, December 2006 (Reaffirmed April 2011). Global Standard Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsUp Time
Definition(s)
Up Time
Time interval during which an item is in an up state. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsTaxonomy
Definition(s)
Taxonomy
Systematic classification of items into generic groups based on factors possibly common to several of the items. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsTag Number
Definition(s)
Tag Number
Number that identifies the physical location of equipment. NOTE For more detailed definitions and interpretations, see Annex C. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsSurveillance Period
Definition(s)
Surveillance Period
Interval of time (calendar time) between the start date and end date of RM data collection. NOTE For more detailed definitions and interpretations, see Annex C. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsSubunit
Definition(s)
Subunit
Assembly of items that provides a specific function that is required for the equipment unit within the main boundary to achieve its intended performance. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsRequired Function
Definition(s)
Required Function
Function or combination of functions of an item that is considered necessary to provide a given service. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsRequired Function
Function, or combination of functions, of an item that is considered necessary to provide a given service. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsReliability
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 StandardsReliability
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 StandardsReliability
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 StandardsReliability
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 StandardsReliability
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 StandardsReliability 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 StandardsReliability
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 StandardsReliability
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 StandardsReliability
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 StandardsReliability
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.
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 StandardReliability
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.
Redundancy
Definition(s)
Redundancy
The ability of a component or system to maintain or restore its function when a single failure has occurred. Redundancy can be achieved, for instance, by the installation of multiple components, systems or alternative means of performing a function.
Source: IMO MSC.1/Circ.1580, GUIDELINES FOR VESSELS AND UNITS WITH DYNAMIC POSITIONING (DP) SYSTEMS, 16 June 2017, International Maritime Organization. Regulatory GuidanceRedundancy
Redundancy means the ability of a component or system to maintain or restore its function when a single failure has occurred. Redundancy can be achieved, for instance, by the installation of multiple components, systems or alternative means of performing a function.
Source: IMO MSC.1/Circ.1580, GUIDELINES FOR VESSELS AND UNITS WITH DYNAMIC POSITIONING (DP) SYSTEMS, 16 June 2017, International Maritime Organization. Regulatory GuidanceRedundancy
Ability of a component or system to maintain its function when one failure has occurred. Redundancy can be achieved, for instance, by installation of multiple components, systems or alternative means of performing a function. Source: Offshore Gangways, DNVGL-ST-0358, DNV GL, September 2017. Global StandardsRedundancy
Additional or alternative systems, sub-systems, assets, or processes that maintain a degree of overall functionality in case of loss or failure of another system, sub-system, asset, or process. From: DHS Risk Lexicon. Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global StandardsRedundancy
The availability of alternate load paths in a platform following the failure of one or more structural components. Source: API RP 2SIM, Structural Integrity Management of Fixed Offshore Structures, First Edition, November 2014. Global StandardsRedundancy
Existence of more than one means for performing a required function- Note: 1 to entry: The aim of redundancy is to provide backup in case of one or several failures of the means
- Note: 2 to entry: Redundancy definitions for passive (cold) standby, active (hot) standby and mixed are given in
- Note: 3 to entry: Redundancy is sometimes (in IEC 61508[2] and IEC 61511[3]) called “fault tolerance”.
Redundancy
The ability of a component or system to maintain or restore its function when a failure of a member or connection has occurred. Redundancy may be achieved for instance by strengthening or introducing alternative load paths. Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global StandardsRedundancy
Additional or alternative systems, sub-systems, assets, or processes that maintain a degree of overall functionality in case of loss or failure of another system, sub-system, asset, or process Sample Usage: A lack of redundancy in access control mechanisms is a vulnerability that can result in a higher likelihood of a successful attack. Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory GuidanceRedundancy
Existence of more than one means for performing a required function. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsRedundancy
Existence of more than one means for performing a required function of an item. NOTE For more detailed definitions and interpretations, see C.1.2. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsRedundancy
Ability of a structure to find alternative load paths following failure of one or more non-critical components, thus limiting the consequences of such failures.- NOTE: All structures having redundancy are statically indeterminate. [ISO 19902:2007, definition 3.39].
Preventive Maintenance
Definition(s)
Preventive Maintenance
Planned action to minimize the likelihood of equipment failure and unscheduled interruptions. Source: API SPEC Q1, Specification for Quality Management System Requirements for Manufacturing Organizations for the Petroleum and Natural Gas Industry, Ninth Edition, June 2013 (Errata 2, March 2014). Global StandardsPreventive Maintenance
Maintenance carried out at predetermined intervals or according to prescribed criteria and intended to reduce the probability of failure or the degradation of the functioning of an item. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsPreventive Maintenance
Planned action to minimize the likelihood of causes of equipment failure and unscheduled interruptions to planned events. Source: API Spec Q2, Specification for Quality Management System Requirements for Service, Supply Organizations for the Petroleum and Natural Gas Industries, Upstream Segment, First Edition, December 2011. Global StandardsPreventive Maintenance
maintenance carried out at predetermined intervals or according to prescribed criteria and intended to reduce the probability of failure or the degradation of the functioning of an item [SOURCE: ISO 14224] Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global StandardsOpportunity Maintenance
Definition(s)
Opportunity Maintenance
Maintenance of an item that is deferred or advanced in time when an unplanned opportunity becomes available. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsOperating Time
Definition(s)
Operating Time
Time interval during which an item is in operating state. NOTE Operating time includes actual operation of the equipment or the equipment being available for performing its required function on demand. See also Table 4. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsOperating Time
Time interval during which an item is in an operating state. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsOperating State
Definition(s)
Operating State
State when an item is performing a required function. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global Standards Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsNon-Critical Failure
Definition(s)
Non-Critical Failure
Failure of an equipment unit that does not cause an immediate cessation of the ability to perform its required function. NOTE Non-critical failures can be categorized as “degraded” (3.7) or “incipient” (3.26). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsModification
Definition(s)
Modification
Combination of all technical and administrative actions intended to change an item. NOTE Modification is not normally a part of maintenance, but is frequently performed by maintenance personnel. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsModification
Combination of all technical and administrative actions intended to change an item. NOTE Modification is not normally a part of maintenance, but is frequently performed by maintenance personnel. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsModification
Change to the design of the equipment which affects material, fit, form or function. Source: IEC 60079-19:2015, Explosive atmospheres – Part 19: Equipment repair, overhaul and reclamation, Edition 3.1, March 2015. Global StandardsModification
Combination of all technical and administrative actions intended to change an item. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsModification:
Modification means a change required by the Regional Supervisor to an EP, DPP, or DOCD (see 30 CFR 550.233(b)(2) and 550.270(b)(2)) that is pending before BOEM for a decision because the OCS plan is inconsistent with applicable requirements. Source: Oil and Gas and Sulphur Operations in the Outer Continental Shelf, 30 CFR 250 (2013). RegulationsMaintenance Man-Hours
Definition(s)
Maintenance Man-Hours
Accumulated duration of the individual maintenance times used by all maintenance personnel for a given type of maintenance action or over a given time interval. NOTE 1 Maintenance man-hours are expressed in units of hours. NOTE 2 As several people can work at the same time, man-hours are not directly related to other parameters like MTTR or MDT (see definitions in Annex C.5). Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. GlobalStandardsMaintainability (General)
Definition(s)
Maintainability (General)
Ability of an item under given conditions of use, to be retained in, or restored to, a state in which it can perform a required function, when maintenance is performed under given conditions and using stated procedures and resources. NOTE For a more detailed definition and interpretation of maintainability, see Annex C. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. Global StandardsMaintainability (General)
Ability of an item under given conditions of use, to be retained in, or restored to, a state in which it can perform a required function, when maintenance is performed under given conditions and using stated procedures and resources. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global StandardsMaintenance Record
Definition(s)
Maintenance Record
Part of maintenance documentation that contains all failures, faults and maintenance information relating to an item. NOTE This record can also include maintenance costs, item availability or up time and any other data where relevant.1Source(s)
1. API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. GlobalStandards
Maintenance Impact
Definition(s)
Maintenance Impact
Impact of the maintenance on the plant or equipment’s function(s). NOTE On the equipment level, two severity classes are defined: critical and non-critical. On plant level, three classes are defined: total, partial or zero impact. Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. GlobalStandardsMaintenance
Definition(s)
Maintenance
Action(s) taken to minimize the likelihood of causes of equipment failure and unscheduled interruptions.- NOTE: This is referred to in API Q2 as “preventive maintenance”.
Maintenance
Upkeep of well control equipment that is performed in accordance with the equipment owner’s preventive maintenance (PM) program and the manufacturer’s guidelines.- NOTE: These procedures may include but are not limited to: inspections, cleaning, polishing, function testing, pressure testing, NDE, and change out of sealing parts and those parts defined in the PM program to be changed either periodically or on a cycle basis.