Failure Rate

Failure Rate

Definition(s)


Failure Rate

Limit, if this exists, of the ratio of the conditional probability that the instant of time, T, of a failure of an item falls within a given time interval, [t, (t + Δt)] and the length of this interval, Δt, when Δt tends to zero, given that the item is in an up state at the beginning of the time interval. See ISO 14224:2006, Clause C.3 for further explanation of the failure rate. NOTE 1 In this definition, t may also denote the time to failure or the time to first failure. NOTE 2 A practical interpretation of failure rate is the number of failures relative to the corresponding operational time. In some cases, time can be replaced by units of use. In most cases, the reciprocal of MTTF (3.1.25) can be used as the predictor for the failure rate, i.e. the average number of failures per unit of time in the long run if the units are replaced by an identical unit at failure. NOTE 3 The failure rate can be based on operational time or calendar time. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global Standards  

Failure Rate

3.1.18 failure rate1   failure rate2 Source: ISO/TR 12489:2013(E) Reliability modelling and calculation of safety systems. Global Standards    
Action Effect

Action Effect

Definition(s)


Action Effect

Effect of actions on structural components. [ISO 19900:2002].
  • EXAMPLE Internal forces, moments, stresses, strains, rigid body motions or elastic deformations.
Source: ISO 19901-7:2013, Petroleum and natural gas industries – Specific requirements for offshore structures – Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units. Global Standards  

Action Effect

Effect of actions on structural components.
  • EXAMPLE   Internal force, moment, stress or strain.
Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global Standards  

Action Effect

Effect of actions on structural components.
  • EXAMPLE Internal forces, moments, stresses, strains, rigid body motions or elastic deformations. [ISO 19904-1:2006, 3.5].
Source: API RP 2MOP, Marine Operations, Upstream Segment, First Edition, July 2010. Global Standards
Deliverability

Deliverability

Definition(s)


Deliverability

Ratio of deliveries to planned deliveries over a specified period of time, when the effect of compensating elements, such as substitution from other producers and downstream buffer storage, is included. Source: ISO 20815:2008, Petroleum, petrochemical and natural gas industries – Production assurance and reliability management. Global Standards  
Structure

Structure

Definition(s)


Structure

Structure means any fixed, moveable or floating structure or installation, and includes a greenhouse gas pipeline, greenhouse gas pumping station, greenhouse gas tank station or greenhouse gas valve station. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. Legislation  

Structure

Structure means any fixed, moveable or floating structure or installation, and includes a petroleum pipeline, petroleum pumping station, petroleum tank station or petroleum valve station. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. Legislation  

Structure

Organized combination of connected components designed to withstand actions and provide adequate rigidity. [ISO 19900:2002]. Source: ISO 19901-7:2013, Petroleum and natural gas industries – Specific requirements for offshore structures – Part 7: Stationkeeping systems for floating offshore structures and mobile offshore units. Global Standards Source: ISO 19900:2013, Petroleum and natural gas industries – General requirements for offshore structures. Global Standards
Top Event

Top Event

Definition(s)


Top Event

The release of a hazard is the first undesired event. This event is called the Top Event (the first Hazardous Event.) The Top Event is at the end of the fault tree and at the beginning of an event tree. Other Related Terms and Definitions: ISO-17776 – Particular hazardous event considered in the development of fault and event trees. 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  

Top Event

Particular hazardous event considered in the development of fault and event trees. 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
Tolerable Risk

Tolerable Risk

Definition(s)


Tolerable Risk

Risk which is accepted in a given context based on the current values of society. 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/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards, Global Standards
Screening Criterion

Screening Criterion

Definition(s)


Screening Criterion

Target or standard used to judge the tolerability of an identified hazard or effect. 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
Risk Evaluation

Risk Evaluation

Definition(s)


Risk Evaluation

Process of comparing the estimated risk against given risk criteria to determine the significance of the risk. Other Related Terms and Definitions: ISO Guide 73 – Process of comparing the estimated risk against given risk criteria to determine the significance of the risk. 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  

Risk Evaluation

Process of comparing the results of risk analysis with risk criteria to determine whether the risk and/or its magnitude is acceptable or tolerable [SOURCE: ISO Guide 73:2009]
  • Note 1 to entry: Risk evaluation assists in the decision about risk treatment.
Source: ISO/IEC 27000:2014, Information technology — Security techniques — Information security management systems — Overview and vocabulary, Third Edition, January 2014. Global Standards  

Risk Evaluation

Judgement, on the basis of risk analysis, of whether a risk is tolerable. 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  

Risk Evaluation

Process of comparing the results of risk analysis (3.6.1) with risk criteria (3.3.1.3) to determine whether the risk (1.1) and/or its magnitude is acceptable or tolerable. NOTE Risk evaluation assists in the decision about risk treatment (3.8.1). Source: ISO Guide 73:2009(E/F), Risk Management – Vocabulary, First Edition, 2009. Global Standards  

Risk Evaluation

Procedure based on the risk analysis to determine whether the tolerable risk has been achieved. Source: ISO/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards, Global Standards  

Risk Evaluation

“Risk evaluation” means the process by which risks are examined in terms of acceptability of the risk considering
  1. regulatory requirements,
  2. needs, issues, and concerns of those affected by, or potentially affected, by the risk, and
  3. what is reasonably practicable under the given circumstances.
Source:  Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. Regulations
Risk Analysis

Risk Analysis

Definition(s)


Risk Analysis

The systematic examination of the components and characteristics of risk. Source: API RP 781 Security Plan Methodology for the Oil and Natural Gas Industries.1st Ed. September 2016. Global Standards  

Risk Analysis

The systematic examination of the components and characteristics of risk. Related Term(s): risk assessment, risk 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 Standards

Risk Analysis

Systematic examination of the components and characteristics of risk.

Source:API STANDARD 780, Security Risk Assessment Methodology for the Petroleum and Petrochemical Industries, First Edition, May 2013. Global Standards

Risk Analysis

Systematic examination of the components and characteristics of risk. Sample Usage: Using risk analysis, the community identified the potential consequences from flooding. Annotation: In practice, risk analysis is generally conducted to produce a risk assessment. Risk analysis can also involve aggregation of the results of risk assessments to produce a valuation of risks for the purpose of informing decisions. In addition, risk analysis can be done on proposed alternative risk management strategies to determine the likely impact of the strategies on the overall risk. Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory Guidance  

Risk Analysis

Systematic uses of information to identify hazards and to estimate risk. Other Related Terms and Definitions: ISO Guide 73 – Systematic uses of information to identify source and to estimate risk ISO-17776 – Use of available information to identify hazards and to estimate risk. 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  

Risk Analysis

Process to comprehend the nature of risk (1.1) and to determine the level of risk (3.6.1.8). NOTE 1 Risk analysis provides the basis for risk evaluation (3.7.1) and decisions about risk treatment (3.8.1). NOTE 2 Risk analysis includes risk estimation. Source: ISO Guide 73:2009(E/F), Risk Management – Vocabulary, First Edition, 2009. Global Standards  

Risk Analysis

Use of available information to identify hazards and to estimate risk. 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  

Risk Analysis

“Risk analysis” means the systematic use of information to identify hazards and to estimate the chance for, and severity of the hazard with respect to worker health and safety. Source:  Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. Regulations  

Risk Analysis

Systematic use of available information to identify hazards and to estimate the risk. Source: ISO/IEC Guide 51:1999, Safety aspects – Guidelines for their inclusion in standards, Global Standards
Accident

Accident

Definition(s)


Accident

“Accident” means a fortuitous event that results in the death of or injury to any person involved in a diving operation (accident). Source: Canada Oil and Gas Diving Regulations, SOR/88-600, February 2013. Regulations Source: Nova Scotia Offshore Area Petroleum Diving Regulations, SOR/95-189, Canada, current to May 31, 2012. Regulations  

Accident

Accident includes the contraction of a disease. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. Legislation  

Accident

Accident means an event that. (a) causes any person to be harmed; or (b) in different circumstances, might have caused any person to be harmed. Source: Health and Safety in Employment Act 1992, Public Act 1992 No 96, New Zealand, as of 1 July 2011. Legislation  

Accident

“Accident” means an incident that results in a hazard causing harm to a worker. Source:  Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. Regulations  

Accident

Event or chain of events which cause, or could have caused, injury, illness and/or damage (loss) to assets, the environment or third parties. Source: ISO 17776:2000, Petroleum and natural gas industries – Offshore production installations – Guidelines on tools and techniques for hazard identification and risk assessment. GlobalStandards  

Accident

See Incident. As low as reasonably practicable (ALARP) To reduce a risk to a level which is ‘as low as reasonably practicable’ involves balancing reduction in risk against the time, trouble, difficulty and cost of achieving it. This level represents the point, objectively assessed, at which the time, trouble, difficulty and cost of further reduction measures become unreasonably disproportionate to the additional risk reduction obtained. Source: OGP Report No. 6.36/210, Guidelines for the Development and Application of Health, Safety and Environmental Management Systems, International Association of Oil & Gas Producers, July 1994. Global Standards  

Accident

An event that causes any person to be harmed, or in different circumstances might have caused any person to be harmed. Source: Approved Code of Practice for Managing Hazards to Prevent Major Industrial Accidents, Health and Safety in Employment Act 1992, Department of Labour, New Zealand, July 1994. Regulatory Guidance
Incident

Incident

Definition(s)


Incident

Occurrence, caused by either human action or natural phenomena, which may cause harm and may require action.

Source:API STANDARD 780, Security Risk Assessment Methodology for the Petroleum and Petrochemical Industries, First Edition, May 2013. Global Standards

Incident

“Incident” means a fortuitous event that compromises or is likely to compromise the safety of, or endangers or is likely to endanger the health, well-being or life of, a person involved in a diving operation (incident). Source: Canada Oil and Gas Diving Regulations, SOR/88-600, February 2013. Regulations Source: Nova Scotia Offshore Area Petroleum Diving Regulations, SOR/95-189, Canada, current to May 31, 2012. Regulations  

Incident

“Incident” means
  1.  any event that causes
    1. a lost or restricted workday injury,
    2. death,
    3. fire or explosion,
    4. a loss of containment of any fluid from a well,
    5. an imminent threat to the safety of a person, installation or support craft, or
    6. pollution;
  2. any event that results in a missing person; or
  3. any event that causes
    1. the impairment of any structure, facility, equipment or system critical to the safety of persons, an installation or support craft, or
    2. the impairment of any structure, facility, equipment or system critical to environmental protection. (incident).
Source: Canada Oil and Gas Drilling and Production Regulations, SOR/2009-315, February 2013. Regulations Source: Drilling and Production Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, March 31, 2011. Regulatory Guidance Source: Nova Scotia Offshore Petroleum Drilling and Production Regulations, SOR/2009-317, Canada, current to May 31, 2012. Regulations  

Incident

Occurrence, caused by either human action or natural phenomena, that may cause harm and that may require action. Sample Usage: DHS plays a role in reducing the risk of a catastrophic incident in the United States. Annotation:
  1. Homeland security incidents can include major disasters, emergencies, terrorist attacks, terrorist threats, wildland and urban fires, floods, hazardous materials spills, nuclear accidents, aircraft accidents, earthquakes, hurricanes, tornadoes, tropical storms, war-related disasters, public health and medical emergencies, law enforcement encounters and other occurrences requiring a mitigating response.
  2. Harm can include human casualties, destruction of property, adverse economic impact, and/or damage to natural resources.
Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory Guidance  

Incident

Any event that caused or, under slightly different circumstances, would likely have caused harm to personnel, an unauthorized discharge or spill or an imminent threat to the safety of an installation, vessel or aircraft. It also includes any event that impairs the function of any equipment or system critical to the safety of personnel, the installation, vessel or aircraft or any event that impairs the function of equipment or system critical to the protection of the natural environment. Note: 10 OSH (NL) 15; OSH (NS) Element 1, Part 1, Section 1.1; INST 70; DPR 1(1) definition of ”incident” and “near-miss”; GR 27 & 28; DVR 6. Source: Incident Reporting and Investigation Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, November 30, 2012. Regulatory Guidance  

Incident

Event, or chain of events, which cause, or could have caused, injury, illness and/or damage (loss) to assets, the environment or third parties. Other Related Terms and Definitions: ISO-17776 – Event, or chain of events, which cause, or could have caused, injury, illness and/or damage (loss) to assets, the environment or third parties. IADC HSE Case Guidelines Issue 02 – Includes all undesired circumstances and occurrences that have the potential to cause accidents. IADC HSE Case Guidelines Issue 02 – (Accident) – Includes any undesired circumstances which gives rise to ill-health or injury, damage to property, plant, products or the environment. 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  

Incident

"Incident" means any occurrence or series of occurrences having the same origin, which causes pollution damage or creates a grave and imminent threat of causing such damage. Source: International Convention on Civil Liability for Bunker Oil Pollution Damage, 2001. Legislation  

Incident

An event or chain of events that has resulted in harmful consequences, such as injuries, illnesses, property damage or environmental impact. Source: IOGP Report No. 510, Operating Management System Framework for controlling risk and delivering high performance in the oil and gas industry, International Association of Oil & Gas Producers, Jun  

Incident

Event or chain of events which cause, or could have caused, injury, illness and/or damage (loss) to assets, the environment or third parties. Source: ISO 17776:2000, Petroleum and natural gas industries – Offshore production installations – Guidelines on tools and techniques for hazard identification and risk assessment. GlobalStandards  

Incident

An occurrence that actually or potentially results in adverse consequences to (adverse effects on) (poses a threat to) an information system or the information that the system processes, stores, or transmits and that may require a response action to mitigate the consequences. Extended Definition: An occurrence that constitutes a violation or imminent threat of violation of security policies, security procedures, or acceptable use policies. Adapted from: CNSSI 4009, FIPS 200, NIST SP 800-53 Rev 4, ISSG Source: NICCS™ Portal Cybersecurity Lexicon, National Initiative for Cybersecurity Careers and Studies (https://niccs.us-cert.gov/glossary) as of 11 November 2015, Global Standards  

Incident

“Incident” means an occurrence that could or does result in a health or safety hazard causing harm or damage including an accident or high potential incident. Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. Regulations  

Incident

An event or chain of events which has caused or could have caused injury, illness and/or damage (loss) to assets, the environment or third parties. (The word ‘accident’ is used by some writers and organisations to denote an incident which has caused injury, illness and/or damage, but the term also has connotations of ‘bad luck’ in common speech, and is therefore avoided by others. In these guidelines, only the term ‘incident’ has been used—in the above sense which embraces the concept of ‘accident’.) Source: OGP Report No. 6.36/210, Guidelines for the Development and Application of Health, Safety and Environmental Management Systems, International Association of Oil & Gas Producers, July 1994. Global Standards  

Incident

An event or chain of events which has caused or could have caused injury, illness and/or damage (loss) to assets, the environment or third parties. (The word ‘accident’ is used by some writers and organisations to denote an incident which has caused injury, illness and/or damage, but the term also has connotations of ‘bad luck’ in common speech, and is therefore avoided by others. In these guidelines, only the term ‘incident’ has been used—in the above sense which embraces the concept of ‘accident’.) Source: OGP Report No. 456, Process Safety – Recommended Practice on Key Performance Indicators, International Association of Oil & Gas Producers, November 2011. Global Standards
Hazards Register

Hazards Register

Definition(s)


Hazards Register

Brief, but complete, summary that demonstrates that hazards have been identified, assessed, and that barriers (both controls and defences) are in place. Other Related Terms and Definitions: ISO-17776 – Document providing a brief, but complete, overview of the identified hazards and the measures necessary to manage them. 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  

Hazards Register

Document providing a brief, but complete, overview of the identified hazards and the measures necessary to manage them. NOTE The hazards register also provides references to more detailed information relevant to a particular hazard. 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  
ETA

ETA

Definition(s)


ETA

Event 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 Guidelines 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  

ETA

Tree-like diagram used to determine alternative potential scenarios arising from a particular hazardous event. NOTE It can be used quantitatively to determine the probability or frequency of different consequences arising from the hazardous event. 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  

ETA

Estimated Time of Arrival. Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards  
Fault Tree Analysis

Fault Tree Analysis

Definition(s)


Fault Tree Analysis

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 Standards  
Event Tree Analysis

Event Tree Analysis

Definition(s)


Event Tree Analysis

Tree-like diagram used to determine alternative potential scenarios arising from a particular hazardous event. NOTE It can be used quantitatively to determine the probability or frequency of different consequences arising from the hazardous event. 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  
Fault Tree

Fault Tree

Definition(s)


 

Fault Tree

In a fault tree the conditions necessary for a failure are presented in a reverse order starting with the unwanted or “top” event. Circumstances leading to this event are then developed. This activity, in itself, is useful in that it logically presents cause combinations. The fault tree is then “resolved” to eliminate duplication (this requires a little expertise in the application of Boolean algebra) and by applying failure estimates at the base of the tree and working up, the likelihood of the “top” event occurring may be estimated as either a probability or a frequency. Source: Approved Code of Practice for Managing Hazards to Prevent Major Industrial Accidents, Health and Safety in Employment Act 1992, Department of Labour, New Zealand, July 1994. Regulatory Guidance  

Fault Tree

Graphical tool used to illustrate the range, probability, and interaction of causal occurrences that lead to a final outcome Sample Usage: A fault tree for machinery was used to diagram the possible points of failure. Annotation:
  1. Fault trees use inductive (backwards) logic; they begin with a final occurrence and work backwards in time to determine the possible causes.
  2. A fault tree can be used to quantitatively estimate the probability of a program or system failure by visually displaying and evaluating failure paths.
  3. Fault trees can identify system components that lack redundancy or are overly redundant.
  4. As an example, consider Figure B. The final outcome, labelled here as Damage to System is shown at the top of the fault tree. All of the events that could lead to Damage to System are diagrammed in the tree beneath the final outcome. Each event either does or does not occur, and the events are interconnected by logical functions OR and AND.
Notice that one event that could result in Damage to System is if a Successful Attack occurs. Successful Attack is one of the final states depicted in the Event Tree example. The occurrence of a Successful Attack depends on 1) an attack being attempted, 2) the failure of Personnel Action to Stop Attack, AND 3) the failure of Security Equipment to Stop Attack. If the probability of an attack being attempted is P0, then the probability of a Successful Attack is the probability that all three of these conditions are met, equal to P0 ×P1 × P2. However, Damage to System can also occur if Natural Disaster occurs, which happens with probability of P3. Assuming that P0 equals 5% or .05, P1 equals 10% or 0.1, P2 equals 30% or 0.3, and P3 equals 20% or 0.2, then the overall probability of Damage to System is calculated as follows: Probability of Damage to System = Probability that Natural Disaster occurs OR Successful Attack occurs. = 1 -[Probability that Natural Disaster does not occur AND Successful Attack does not occur] = 1 -[(1 -P3) × (1 – P0 × P1 × P2)] = 1 -[0.8 × (1 -0.0015)] = 0.2012 Therefore, the probability of Damage to the System from all possible hazards is approximately 20%. f tree Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory Guidance

Fault Tree

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 Standards    
Event Tree

Event Tree

Definition(s)


 

Event Tree

An event tree starts with an initiating event then works forward to develop a number of possible outcomes. At each branch the system (or person) is considered to have “failed” or “not failed” and probabilities are assigned that provide a quantitative estimate of the likelihood of each outcome. Source: Approved Code of Practice for Managing Hazards to Prevent Major Industrial Accidents, Health and Safety in Employment Act 1992, Department of Labour, New Zealand, July 1994. Regulatory Guidance  

Event Tree

Definition: graphical tool used to illustrate the range and probabilities of possible outcomes that arise from an initiating event. Sample Usage: Analysts used an event tree to diagram possible outcomes from a terrorist attack. Annotation:
  1. Event trees use forward logic; they begin with an initiating event and work forward in time to determine the possible outcomes.
  2. The probabilities used in event trees are conditional probabilities because they are based on the assumption that the initiating event has already occurred. (See Probability annotation for a description of conditional probability.)
  3. As an example, consider Figure A. The initiating event is an Attack Attempted. From the initiating event, the tree branches into a sequence of random variables, called events. The branching point at which a new random event is introduced is called a node and is depicted by a circle.
The first of these random events is Personnel Action to Stop Attack. The Personnel Action to Stop Attack is successful with probability 1-P1 and fails to stop the attack with probability P1. If Personnel Action to Stop Attack is successful, then the branch leads to the final outcome of Unsuccessful Attack, No Damage (Scenario A). If Personnel Action to Stop Attack is not successful, then the branch leads to the next node representing the random event of whether the Security Equipment to Stop Attack is successful or not with probabilities of 1-P2 and P2 respectively. If the Security Equipment to Stop Attack is successful then the branch leads to the final outcome of Unsuccessful Attack, No Damage (Scenario B). If Security Equipment to Stop Attack fails then the branch leads to the final outcome of Successful Attack, Damage to System (Scenario C). Assuming that P1 equals 10% or 0.1 and P2 equals 30% or 0.3, then the conditional probabilities of a Successful and Unsuccessful Attack, given that the initiating event occurs and an attack is attempted, are calculated as follows: Probability of Successful Attack given that an attack is attempted: = Probability of Scenario C = Probability that Personnel Action to Stop Attack fails and Security Equipment to Stop Attack fails. = P1× P2 = 0.1 × 0.3 = 0.03 Therefore, the conditional probability of a Successful Attack, given the attack is attempted, is 3%. Probability of Unsuccessful Attack given that an attack is attempted: = Probability of Scenario A or Scenario B occurring = Probability that Personnel Action to Stop Attack is successful or Security Equipment to Stop Attack is successful. = (1 -P1) + [P1 × (1 -P2)] = 0.9 + (0.1 × 0.7) = 0.97 Therefore, the conditional probability of an Unsuccessful Attack, given that the attack is attempted, is 97%. Notice that the Probability of Successful Attack plus the probability of Unsuccessful Attack equals one because there are no alternative outcomes. event tree Event trees differ from fault trees by starting with an initiating event and moving forward in time to determine possible final outcomes. Fault trees start with an outcome and work backwards in time to determine the range of events that may have caused the outcome. Source: DHS Risk Lexicon, U.S. Department of Homeland Security, 2010 Edition. September 2010 Regulatory Guidance  

Event Tree

Tree-like diagram used to determine alternative potential scenarios arising from a particular hazardous event. NOTE It can be used quantitatively to determine the probability or frequency of different consequences arising from the hazardous event. 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  

 
Survival Condition

Survival Condition

Definition(s)


Survival Condition

“Survival condition”, with respect to a mobile offshore platform, means the condition of the platform when it is subjected to the most severe environmental conditions determined pursuant to section 45 (condition de survie). Source: Canada Oil and Gas Installations Regulations, SOR/96-111, Canada, current to May 1, 2014. Regulations Source: Canada Oil and Gas Installations Regulations, SOR/96-118, February 2013. Regulations  

Survival Condition

A condition during which a unit may be subjected to the most severe environmental loadings for which the unit is designed. Drilling or similar operations may have been discontinued due to the severity of the environmental loadings. The unit may be either afloat or supported on the sea bed, as applicable. Source: Offshore Standard DNV-OS-C101, Design of Offshore Steel Structures, General (LRFD Method, Det Norske Veritas, April 2011. Global Standards  

Survival Condition

“Survival condition”, with respect to a mobile platform, means the condition of the platform when it is subjected to the most severe environmental conditions determined pursuant to section 44; condition de survie. Source: Nova Scotia Offshore Petroleum Installations Regulations, SOR/95-191, Canada, current to May 31, 2012. Regulations  

Survival Condition

A severe storm condition during which a unit may be subjected to the most severe environmental loadings for which the unit is designed. Drilling or similar operations may have been discontinued due to the severity of the environmental loadings. The unit may be either afloat or supported on the sea bed, as applicable. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 1, Regulations, June 2013, Lloyd’s Register, Global Standards
Board

Board

Definition(s)


Board

“Board” means the National Energy Board established by section 3 of the National Energy Board Act (Office). Source: Canada Oil and Gas Drilling and Production Regulations, SOR/2009-315, February 2013. Regulations Source: National Energy Board Act, R.S.C., 1985, c. N-7, Canada, current to April 29, 2013. Legislation  

Board

“Board” means the Canada-Nova Scotia Offshore Petroleum Board established by the joint operation of section 9 of this Act and section 9 of the Provincial Act; Office. Source: Canada-Nova Scotia Offshore Petroleum Resources Accord Implementation Act, S.C. 1988, c. 28, Canada, current to May 26, 2013. Legislation  

Board

The National Energy Board, Canada-Newfoundland and Labrador Offshore Petroleum Board or the Canada-Nova Scotia Offshore Petroleum Board, as the case may be. Source: Environmental Protection Plan Guidelines, The Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada-Nova Scotia Offshore Petroleum Board, and National Energy Board, Canada, March 31, 2011. Regulatory Guidance Source: Safety Plan Guidelines, The Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada-Nova Scotia Offshore Petroleum Board, and National Energy Board, Canada, March 31, 2011. Regulatory Guidance  

Board

A body of elected or appointed individuals who jointly govern the activities of the company. The board is normally the highest authority for management of the company. The authority is conferred on the board by the shareholders or owners of the company who set articles constituting the responsibilities, rules and limitations within which the board operates. Source: IOGP Report No. 510, Operating Management System Framework for controlling risk and delivering high performance in the oil and gas industry, International Association of Oil & Gas Producers, June 2014. Global Standards  

Board

“Board” means the Canada-Nova Scotia Offshore Petroleum Board. Source:  Nova Scotia Offshore Petroleum Occupational Health & Safety Requirements, Canada-Nova Scotia Offshore Petroleum Board, Canada, December 2000. Regulations  

Board

“Board” means the Environmental Studies Management Board established by subsection 78(1); Conseil. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. Legislation

Board

Board means the National Offshore Petroleum Safety and Environmental Management Authority Board continued in existence by section 653. Source: Offshore Petroleum and Greenhouse Gas Storage Act 2006, Australia, amended 2012. Legislation  

Board

"Board" means the Oil Industry Development Board established under section 3. Source: The Petroleum and Natural Gas Regulatory Board Act, 2006, No. 19 of 2006, India, amended as of May 2013. Legislation
F&G

F&G

Definition(s)


F&G

Fire and gas. Source:  DNVGL-RP-G108, Cyber security in the oil and gas industry based on IEC 62443, DNV GL, September 2017. Global Standards Source: API STD 521, Pressure-relieving and Depressuring Systems, Sixth Edition, January 2014. 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: ISO 13702:2015, Petroleum and natural gas industries — Control and mitigation of fires and explosions on offshore production installations — Requirements and guidelines, Second Edition, August 2015. Global Standards Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
ERS

ERS

Definition(s)


ERS

Emergency response strategy. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards  
ERP

ERP

Definition(s)


ERP

Emergency response plan. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards Source: NOGEPA Guideline 14, Helideck Operations and Procedures Manual, Netherlands, Version 2, December 2011. Global Standards  
EPIRB

EPIRB

Definition(s)


EPIRB

Emergency position-indicating radio beacon. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards  
Tertiary Method

Tertiary Method

Definition(s)


Tertiary Method (for escape to the sea)

Method which relies considerably on the individual’s own action. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
Temporary Refuge

Temporary Refuge

Definition(s)


Temporary Refuge (TR)

The facilities provided for monitoring and control of the incident and protecting personnel prior to evacuation. 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  

Temporary Refuge (TR)

Place provided where personnel can take refuge for a predetermined period while investigations, emergency response, and evacuation preplanning are undertaken. Source: ISO 13702:2015, Petroleum and natural gas industries — Control and mitigation of fires and explosions on offshore production installations — Requirements and guidelines, Second Edition, August 2015. Global Standards  

Temporary Refuge

Place provided where personnel can take refuge for a predetermined period while investigations, emergency response and evacuation preparations are undertaken [SOURCE: ISO 15544:2000, 2.1.37, modified, Note 1 to entry has been omitted.] 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

Temporary Refuge

Place provided where personnel can take refuge for a predetermined period while investigations, emergency response and evacuation preparations are undertaken. NOTE A temporary refuge, where provided, need not necessarily be useable under all accident scenarios. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards  

Temporary Refuge

This is a designated area that is to provide adequate facilities to protect the personnel from fire, explosion and associated hazards during the period for which they may need to remain on a unit following an uncontrolled incident, and for enabling their evacuation, escape and rescue. It is also to provide adequate facilities for monitoring and control of any major incident. Source: Rules and Regulations for the Classification of Mobile Offshore Units, Part 7, Safety Systems, Hazardous Areas and Fire, June 2013, Lloyd’s Register, Global Standards
TR

TR

Definition(s)


Temporary Refuge (TR)

The facilities provided for monitoring and control of the incident and protecting personnel prior to evacuation. 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: API RP 2FB, Recommended Practice for the Design of Offshore Facilities Against Fire and Blast Loading, First Edition, April 2006. Global Standards  

TR

Temporary refuge. 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: 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: ISO 13702:2015, Petroleum and natural gas industries — Control and mitigation of fires and explosions on offshore production installations — Requirements and guidelines, Second Edition, August 2015. Global Standards Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards  

TR

Place provided where personnel can take refuge for a predetermined period while investigations, emergency response and evacuation preparations are undertaken [SOURCE: ISO 15544:2000, 2.1.37, modified, Note 1 to entry has been omitted.] 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  

TR

Place provided where personnel can take refuge for a predetermined period whilst investigations, emergency response and evacuation preparations are undertaken. NOTE A temporary refuge, where provided, need not necessarily be useable under all accident scenarios. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
Survival Suit

Survival Suit

Definition(s)


Survival Suit

Protective suit made of materials which reduce body heat-loss of a person wearing it in cold water. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
Secondary Method

Secondary Method

Definition(s)


Secondary Method, of Evacuation

Method of leaving the installation in an emergency which can be carried out in a fully controlled manner under the direction of the person in charge, independent of external support. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
Rescue

Rescue

Definition(s)


Rescue

"Rescue". An operation to retrieve persons in distress, provide for their initial medical or other needs, and deliver them to a place of safety. Source: IMO Resolution MSC.70(69), adoption of amendments to the International Convention on Maritime Search and Rescue (SAR), 1979, 18 May 1998, International Maritime Organization. Legislation  

Rescue

Process by which those who have entered the sea directly or in survival craft/liferafts are retrieved to a place where medical assistance is available. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards
Primary Method

Primary Method

Definition(s)


Primary Method, of Evacuation

Preferred method of leaving the installation in an emergency which can be carried out in a fully controlled manner under the direction of the person in charge. Source: ISO 15544:2000, Petroleum and natural gas industries – Offshore production installations – Requirements and guidelines for emergency. Global Standards