scenario methodoology

ScenarioMethodology

David AlexanderUniversity College London

Wisdom: ability to take decisionson the basis of principles,experience and knowledge

Knowledge: understanding of howthings function (or should function)

Information: description ofphysical and social situations

Data: basic facts and statistics

COMMUNICATION

Source: Yi-Fu Tuan..?

DETERMINISMCause Effect

PROBABILITY(constrained uncertainty)

Cause Single, multiple or cascading effects

THE KNOWN

THE UNKNOWN

PURE UNCERTAINTYCausal relationship

unknown

Greyarea

known knowns- things we

know

Modified Rumsfeld Classification

unknown knowns -things we

don't realisewe know

known unknowns -things we

know we don't know

unknown unknowns -things we

don't know we don't know

Cascading effects

Collateral vulnerability

Secondarydisasters

Interaction between risks

Climatechange

Probability

Indeterminacy

"Fat-tailed" (skewed)distributionsof impacts

Controllability

Controllable Uncontrollable

Uncertainty

HighAdaptive

managementScenarioplanning

Low Optimal control Hedging

Scenario planning in relation touncertainty and controllability

RESILIENCE

Social

Tech

nica

l

Physical

Psych

ological

naturalsocial

technologicalintentionalcompoundcascading

CLIMATE CHANGEADAPTATION

DISASTER RISKREDUCTION

SUSTAINABILITYSCIENCE

OTHER HAZARDSAND RISKS

scenario: Latin scena or scene: "postulatedsequence or development of events"

"focussed descriptions of fundamentally different futures presented in coherent

script-like or narrative fashion"(Schoemaker 1993)

"hypothetical sequences of eventsconstructed for the purpose of focussing

attention on causal processes anddecision-points" (Kahn and Wiener 1967).

Definitions

Scenario: "a systemic method for thinkingcreatively about possible complex anduncertain futures. The central idea...is to consider a variety of possiblefutures that include many of the

important uncertainties in the systemrather than to focus on the accurate

prediction of a single outcome."

(Peterson et al. 1993)

Herman Kahn 1960s, Rand Corporation,Santa Monica, CAthe problem of projecting economicchanges into an uncertain future

Royal Dutch Shell 1980s(Pierre Wack)possible fluctuations in the future price of oil.

History of the scenario"socio-economic futurology"

Mitigation

Scenario methods fordisaster risk reduction

Hypotheticalscenarios

Hazard

Response Vulnerability

RiskImpact

evolution

developmentof thescenarioevolution

timezero

formal evaluation of theoutcome of the scenario

consequencesat time n

Scenariomethodologyin planning

consequencesat time 2

consequencesat time 1

referenceevent

initialconditions

evaluation ofthe progress

of the scenario

historicalanalysis

hypotheticalingredients

C

C

CC

EE

E

E E E

Event

EventC – causeE - effect

C

E

E

E

E

C

E/C

E

E

E

E

E

E

E

E

E/C

(a) (b)

MAGNITUDE& FREQUENCY

KNOWLEDGESCIENCE

LEGISLATION

IMPLEMENTATION

COMPLIANCE

LAG

LAG

LAG

CUMULATIVELAG

EVENTS

Learningprocesses

Improvedsafety

Lessonlearned

Change andinnovation

Experienceand theory

Recognition andcomprehension

Lesson tobe learned

• Unexpected event

• New circumstance

• Error• New

practice

Personalor privateinterestsPublic

interestCultural

acceptability

LESSONS...LEARNED?

Sustainablelessons Uncertainty,

unpredictability

LESSONS...LEARNED?

Incentivesto learn

• a model simplifies reality inorder to make it understandable

• scenarios help bridge the gap betweentheoretical studies and the need tosolve pressing practical problems.

Scenarios are a form ofcommunications model

• scenario modelling is a technique forelucidating situations in the face ofuncontrollable, irreducible uncertainty

• scenarios must strike a balancebetween continuity and surprise

• scenarios involve a range of possibleoutcomes - the envelope of uncertainty.

Conclusions

• chunking: aggregation of smallquanta of knowledge into meaningfulassemblages

'hedging': to limit or qualify byintroducing conditions or exceptions

• scenarios are moreflexible than forecasts.

Conclusions

david.alexander@ucl.ac.ukwww.slideshare.net/dealexander

www.emergency-planning.blogspot.com