151:. Thus, a bow-tie analysis is centred on an energy-based event. The need for energy sources in any damage process had been noted by Lewis DeBlois as early as 1926 as well as Gibson and Haddon in the decade prior to the introduction of the bow-tie diagram. It is evident that any central event may be originated by more than one mechanism and that, following the release of energy, a number of different outcomes may result. As Rowe made clear, it is these various unwanted outcomes that produce the adverse consequences of injury, damage etc.
120:
194:), spurious pressurization above design limits, inadvertent opening, etc. Shown to the right of the central event, are the results/outcomes of the release (e.g., noise, blast overpressure propagation, flying debris, loss of fluid, etc.) When mechanisms and outcomes and subsequently routes to adverse consequences are understood, the analyst can ensure that control measures (often now called
30:
initiating mechanisms on the left (being where reading diagrams starts) and resulting outcomes and associated consequences (such as injury, loss of property, damage to the environment, etc.) on the right. Needed control measures, or barriers, can be identified for each possible path from mechanisms to the final consequences. The shape of the diagram resembles a
57:. The diagram follows the same basic principles as those on which fault tree analysis and event tree analysis are based, but, in being far less complex than these, is attractive as a means of rapidly establishing an overall scope of risk concerns for an organisation, only some few of which may justify those more rigorous and logical methods.
104:
use the same principle: Things go wrong, there is a reason for that and a result too, with the result generating the adverse consequences. The bow-tie diagram introduces the concept of a central energy-based event (the "bow tie knot") in which the damaging properties of the energy are no longer under
48:
Bow-tie analysis is used to display and communicate information about risks in situations where an event has a range of possible causes and consequences. A bow tie is used when assessing controls to check that each pathway from cause to event and event to consequence has effective controls, and that
131:
The fact that scientific effort benefits greatly from a focus on the process giving rise to the phenomenon of interest is well known in several scientific domains, as noted by
William Haddon. The generalized time sequence model (GTSM) was developed in the 1970s by Viner as a process model suited to
29:
used to describe a possible damage process in terms of the mechanisms that may initiate an event in which energy is released, creating possible outcomes, which themselves produce adverse consequences such as injury and damage. The diagram is centred on the (generally unintended) event with credible
142:
in which the energy necessary to bring about the ultimate undesired consequences is released. In
William Rowe’s seminal work, which explained half of the process of damage, the event of interest is defined as what produces outcomes and consequences of interest and outcomes as what results from an
178:, such as injury, loss of property, damage to the environment, etc. on the right. This left to right flow of the process is also a time axis. Control barriers, either hard/engineered or administrative/procedural, are identified for each path from the mechanisms to the final outcomes.
127:
Bow-tie diagrams contribute to the identification, description and understanding of the different types of hazards that can arise in a given situation, facility or production process. They also help identify the relevant risk control measures (barriers) for a given hazard.
221:. However, a different type of bow-tie diagram exists that is more apt at supporting quantified risk analysis. This diagram is essentially the combination of a fault tree and an event tree and maintains the Boolean and probabilistic features of those approaches.
198:) exist to stop the initiating mechanisms from resulting in the central event and the central event from leading to the ultimate unwanted outcomes and consequences. Left-hand side (mechanism) control measures are, in this example, external and internal surface
181:
For example, pressure in a process vessel is a form of energy that can be released if containment is breached (the central event). Possible mechanisms for breach of containment, shown to the left, include structural degradation
143:
event. Derek Viner resolved this circularity by defining the event as "the point in time when control is lost of the potentially damaging properties of the energy source of interest." This is sometimes referred to as the
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understanding this process to the phenomenon of unwanted damage. Bow-tie diagrams are a simplified extract of this, conceived of (and then named by students) during a lecture to assist explanation.
217:
Bow-tie diagrams are typically a qualitative tool, used for simple damage process analysis as well as for illustrative purposes, such as in training courses to plant operators and in support of
45:(analyzing the consequences), although it can maintain the quantitative, probabilistic aspects of the fault and event tree when it is used in the context of quantified risk assessments.
773:
Bernsmed, K.; Frøystad, C.; Meland, P.H.; Nesheim, D.A.; Rødseth, Ø.J. (2018). "Visualizing Cyber
Security Risks with Bow-Tie Diagrams". In Liu, P.; Mauw, S.; Stolen, K. (eds.).
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Gibson, J. (1961). "The
Contribution of Experimental Psychology to the Formulation of the Problem of Safety: A Letter for Basic Research". In Jacobs, Herbert J. (ed.).
587:
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failures) are recognized. It can be used proactively to consider potential events and also retrospectively to model events that have already occurred, such as in an
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of
Australia), who drew it as an aid to visualization of his generalized time sequence model (GTSM) for damage processes. The more complex risk analysis tools of
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is considered to be the first major company to successfully integrate bow-tie diagrams into their business practices, at least since the early 1990s.
214:. Outcome (right-hand side) control measures in this example would include nearby structures designed to withstand modelled blast overpressure.
421:
335:
775:
Graphical Models for
Security. 4th International Workshop, GraMSec 2017, Santa Barbara, CA, USA, August 21, 2017, Revised Selected Papers
92:, Australia in 1979. Other sources point to Derek Viner (in the same year) at the then Ballarat College of Advanced Education (now the
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Several software packages are available in the market for bow-tie diagram creation and management.
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A bow-tie diagram can be considered as a simplified, linear, and qualitative representation of a
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It has been commonly noted that the earliest mention of the bow-tie methodology appeared in the
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Bow-tie diagrams are used in various disciplines and domains, including for example:
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Bow-tie diagrams are used in several industries, such as oil and gas production, the
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50:
644:
Haddon, Jr., William (1973). "Energy Damage and the Ten
Countermeasure Strategies".
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Donaldson, Craig (December 2016). "Time for OHS to
Understand the Science of Risk".
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de
Ruijter, A.; Guldenmund, F. (2016). "The Bowtie Method: A Review".
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Occupational Risk
Control: Predicting and Preventing the Unwanted
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Symbolic representation of accident path and safety barriers
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control so that they result in outcomes and consequences.
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Industrial Safety Organization for Executive and Engineer
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factors that could cause controls to fail (including
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41:(analyzing the cause of an event) combined with an
614:Risk Assessment: Theory, Methods, and Applications
342:. IEC 31010 (2.0 ed.). Genève, Switzerland:
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760:Association for the Aid of Crippled Children
426:Risk Management – Risk Assessment Techniques
340:Risk Management – Risk Assessment Techniques
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756:Behavioral Approaches to Accident Research
575:"Practical Application of Bowtie Analysis"
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430:International Electrotechnical Commission
344:International Electrotechnical Commission
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84:(ICI) course notes of a lecture on
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234:Occupational safety and health
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729:DeBlois, Lewis Amory (1926).
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82:Imperial Chemical Industries
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498:UK Civil Aviation Authority
304:Bow Ties in Risk Management
147:(a fault-tree term) or the
34:, after which it is named.
10:
840:
660:10.1177/001872087301500407
550:. No. December 2016.
388:10.1016/j.ssci.2016.03.001
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708:. pp. 29, 456, 462.
700:Rowe, William D. (1977).
737:McGraw-Hill Book Company
612:Rausand, Marvin (2011).
493:"Introduction to Bowtie"
90:University of Queensland
704:. New York, N.Y. etc.:
225:Use in various domains
204:pressure safety valves
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706:John Wiley & Sons
618:John Wiley & Sons
460:Viner, Derek (2015).
308:John Wiley & Sons
300:Energy Institute (EI)
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94:Federation University
250:Information security
212:condition monitoring
154:Credible initiating
525:"Bowties – History"
102:event tree analysis
98:fault tree analysis
824:Safety engineering
758:. New York, N.Y.:
735:. New York, N.Y.:
702:An Anatomy of Risk
554:. pp. 18–22.
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62:process industries
51:management systems
809:Accident analysis
788:978-3-319-74860-3
627:978-0-470-63764-7
616:. Hoboken, N.J.:
475:978-1-4724-1970-5
439:978-2-8322-6989-3
353:978-2-8322-6989-3
306:. Hoboken, N.J.:
158:(which some call
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382:: 211–218.
208:maintenance
803:Categories
529:BowTie Pro
269:References
156:mechanisms
43:event tree
39:fault tree
676:0018-7208
668:1547-8181
560:1837-4980
466:Routledge
404:0925-7535
396:1879-1042
188:corrosion
145:top event
814:Diagrams
588:Archived
509:17 March
503:Archived
424:(2019).
338:(2019).
302:(2018).
200:coatings
196:barriers
184:abrasion
172:outcomes
164:triggers
66:aviation
684:4743998
597:14 July
260:Finance
192:fatigue
168:threats
137:central
76:History
70:finance
32:bow tie
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591:(PDF)
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256:risks
236:(OSH)
140:event
25:is a
783:ISBN
710:ISBN
680:PMID
672:ISSN
622:ISBN
599:2023
556:ISSN
511:2024
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312:ISBN
252:and
210:and
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422:ISO
418:IEC
384:doi
336:ISO
332:IEC
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
