A worst-case scenario is a concept in risk management wherein the planner, in planning for potential

disaster A disaster is a serious problem occurring over a short or long period of time that causes widespread human, material, economic or environmental loss which exceeds the ability of the affected community or society to cope using its own resources ...

s, considers the most severe possible outcome that can reasonably be projected to occur in a given situation. Conceiving of worst-case scenarios is a common form of

strategic planning Strategic planning is an organization's process of defining its strategy or direction, and making decisions on allocating its resources to attain strategic goals. It may also extend to control mechanisms for guiding the implementation of the st ...

, specifically

scenario planning Scenario planning, scenario thinking, scenario analysis, scenario prediction and the scenario method all describe a strategic planning method that some organizations use to make flexible long-term plans. It is in large part an adaptation and gener ...

, to prepare for and minimize contingencies that could result in

accident An accident is an unintended, normally unwanted event that was not directly caused by humans. The term ''accident'' implies that nobody should be blamed, but the event may have been caused by unrecognized or unaddressed risks. Most researche ...

quality Quality may refer to: Concepts *Quality (business), the ''non-inferiority'' or ''superiority'' of something *Quality (philosophy), an attribute or a property *Quality (physics), in response theory *Energy quality, used in various science discipli ...

problems, or other issues.

Development and use

The worst-case scenario is " e of the most commonly used alternative scenarios".Charles Yoe, ''Principles of Risk Analysis: Decision Making Under Uncertainty'' (2011), p. 429-30. A

risk manager In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environme ...

may request "a conservative risk estimate representing a worst-case scenario" in order to determine the latitude they may exercise in planning steps to reduce risks.Nicholas P. Cheremisinoff, ''Environmental Technologies Handbook'' (2005), page 73-74. Generally, a worst-case scenario "is settled upon by agreeing that a given worst case is bad enough. However, it is important to recognize that no worst-case scenario is truly without potential nasty surprises".James A. Dewar, ''Assumption-Based Planning: A Tool for Reducing Avoidable Surprises'' (2002), p. 27. In other words, ‘ “worst-case scenario” is never the worst case’, both because situations may arise that no planner could reasonably foresee, and because a given worst-case scenario is likely to consider only contingencies expected to arise in connection with a particular disaster. The worst-case scenario devised by a seismologist might be a particularly bad earthquake, and the worst-case scenario devised by a meteorologist might be a particularly bad hurricane, but it is unlikely that either of them will devise a scenario where a particularly bad storm occurs at the same time as a particularly bad earthquake. The definition of a worst-case scenario varies by the field to which it is being applied. For example, in

environmental engineering Environmental engineering is a professional engineering discipline that encompasses broad scientific topics like chemistry, biology, ecology, geology, hydraulics, hydrology, microbiology, and mathematics to create solutions that will protect and a ...

", " worst-case scenario is defined as the release of the largest quantity of a regulated substance from a single vessel or process line failure that results in the greatest distance to an endpoint". In this field, " in other fields, the worst-case scenario is a useful device when low probability events may result in a catastrophe that must be avoided even at great cost, but in most health risk assessments, a worst-case scenario is essentially a type of bounding estimate". In

computer science Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...

, the best, worst, and average case of a given algorithm express what the resource usage is at least, at most and on average, respectively. For many individuals, a worst-case scenario is one that would result in their own death.George J. Annas, ''Worst Case Bioethics: Death, Disaster, and Public Health'' (2010), p. xi-xii.

Criticisms

A number of criticisms have been leveled against the use of worst-case scenarios. In some cases, a conceivable worst-case scenario within a field may be so far beyond the capacity of participants to deal with that it is not worth the effort to develop or explore such a scenario; where this is possible, it is "important to evaluate whether the development of a worst-case scenario is reasonable and desirable". Entities that rely on such scenarios in planning may be led to plan too conservatively to take advantage of the usual absence of such scenarios, and may waste resources preparing for highly unlikely contingencies. At the extreme, it has been argued that the use of worst-case scenarios in disaster preparedness and training causes people to become conditioned to set aside ethical concerns and to over-react to lesser disasters. Ben-Haim and

Elishakoff Isaac Elishakoff is a Distinguished Research Professor in the Ocean and Mechanical Engineering Department in the Florida Atlantic University, Boca Raton, Florida. He is an authoritative figure in the broad area of mechanics. He has made several ...

et al. and Hlavacek et al.Hlavacek, Ivan, Jan Chleboun, and Ivo Babuska. Uncertain input data problems and the worst scenario method. Elsevier, 2004. developed the worst-case analysis based on convex constraints, representing uncertainty in applied mechanics.

References

{{reflist Risk management Systems thinking

Development and use

Criticisms

See also

References