A guide to how to build scenarios.

1. SCENARIO METHODOLOGY FOR
PLANNING FUTURE ACTIVITIES
David Alexander
Professor of Risk and Disaster Reduction

2. SCENARIOS ARE THE BASIS
OF EMERGENCY PLANNING

3. T.S. Eliot (1934), The Rock
Where is the life we have lost in living?
Where is the wisdom we have lost in knowledge?
Where is the knowledge we have lost in information?

4. Wisdom: ability to take decisions on the basis
of principles, experience and knowledge
Knowledge: understanding of how
things function (or should function)
Information: description of
physical and social situations
Data: basic facts and statistics
DIKW pyramid

5. DETERMINISM
Cause Effect
PROBABILITY
(constrained uncertainty)
Cause Single, multiple
or cascading effects
THE KNOWN
THE UNKNOWN
PURE UNCERTAINTY
Causal relationship unknown
Grey area

6. Modified Rumsfeld Classification
known knowns
things we know
unknown knowns
things we don't
realise we know
known unknowns
things we know
we don't know
unknown unknowns
things we don't know
we don't know
Tractable

7. Collateral effects ("fallout")
Cascading effects
Concurrent events and context
Bigger-than-expected events
Secondary impacts
Probability
Indeterminacy
Certainty

8. Controllability
Controllable Uncontrollable
Uncertainty
High
Adaptive
management
Scenario
planning
Low Optimal control Hedging
Scenario planning in relation to
uncertainty and controllability
Scenario
planning

9. Scenario (n.): A postulated or projected situation
or sequence of potential future events;
(also) a hypothetical course of events in the past,
intended to account for an existing situation, set of facts, etc.
More generally: a set of circumstances; a pattern of events.
(OED)
A reconstruction of past events (what happened………?)
or...
A hypothetical exploration of future ones (what if………?)

10. 'Backcasting'
scenario,
6-3-1987

11. Forecasting scenario

12. "focussed descriptions of fundamentally
different futures presented in coherent
script-like or narrative fashion"
(Schoemaker 1993)
"hypothetical sequences of events
constructed for the purpose of focussing
attention on causal processes and
decision-points" (Kahn and Wiener 1967)

13. Scenario: "a systemic method for thinking
creatively about possible complex and
uncertain futures. The central idea ... is to
consider a variety of possible futures that
include many of the important uncertainties in
the system rather than to focus on the
accurate prediction of a single outcome.
Peterson, G.D., G.S. Cumming and S.R. Carpenter 1993. Scenario planning:
a tool for conservation in an uncertain world. Conservation Biology 17(2): 358-366.

14. History of the scenario
"socio-economic futurology"
Herman Kahn 1960s, Rand Corporation, Santa Monica, CA
the problem of projecting economic
changes into an uncertain future
Royal Dutch Shell 1980s
(Pierre Wack)
possible fluctuations in
the future price of oil

15. Academic
knowledge
producer
Simple phenomenon
Complex analysis
Beneficiary
(knowledge
user)
barrier of
technical
complexity
Unsatisfactory
outcome

16. A scenario is a form of communications model.
A model simplifies reality in order
to make it understandable.
Scenarios help bridge the gap between
theoretical studies and the need
to solve pressing practical problems.

17. Examples of the use of scenario methods
• mitigation: scenarios of vulnerability
of the built environment
• preparation: scenarios for training
of emergency personnel
• emergency response: warning
and evacuation scenarios
• recovery: economic planning
scenarios for recovery
• reconstruction: scenarios of
economic conditions of reconstruction

18. Plan
Apparent
chaos Model
Testing
Disaster
Result
Feedback
and revision
Feedback
andrevision
Evaluation

19. A systems approach to scenario-building
OutputInput Transformation
"Grey box"

20. evolution
development
of the
scenario
evolution
time
zero
formal evaluation of the
outcome of the scenario
consequences
at time n
consequences
at time 2
consequences
at time 1
reference
event
initial
conditions
evaluation of
the progress
of the scenario
historical
analysis
hypothetical
ingredients
HOW WE USE SCENARIOS
IN EMERGENCY PLANNING

21. HOW TO BUILD
SCENARIOS

22. Fundamental elements of scenarios:-
• impact of a decision: size,
complexity, area involved
• basic rules of operation: duration
of the scenario, timescales
• logistical factors
• dynamics of scenario development
• goals to be achieved: types of
responses and outcomes required
• complications and setbacks

23. Ingredients of a scenario
the basic "building blocks"
• ground rules
• basic logistical factors
• the roles of participants
• the objectives to be reached
• a context of decision: vulnerability, pitfalls, risk
• complicating factors or setbacks
• impacts and reactions
• possible secondary consequences
• a reference event
- it occurs at time zero
- what, where, when, who?

24. More building blocks
• basic rules of operation (duration
of the scenario, timescales)
• objectives to be reached
(and type of response required)
• types of interactions
• priorities of outcomes

25. Learning
processes
Improved
safety
Lesson
learned
Change and
innovation
Experience
and theory
Recognition and
comprehension
Lesson to
be learned
• Unexpected
event
• New
circumstance
• Error
• New practice

26. Scenario-building processes
• a chain of carefully specified consequences
- impacts and reactions
- secondary impacts and pitfalls
• a logical explication of the chain of consequences
• careful examination of all assumptions
on which developments are based
• testing of assumptions
• gauging of the effectiveness of
particular remedial measures

27. Some things to consider
• vulnerabilities
• risk analysis
• legal and jurisdictional responsibilities
• resource audit
• decision-making chain
• integrity of procedures
• communication, dissemination and information

28. Scenarios can be used for situations with:
• differences of opinion
• chronic uncertainty
• scarcity of resources
• things that go wrong
• information and task overload
• problems to solve in short timespans

29. Scenario-building in ten steps
1. Define objectives
2. Define components of scenario (building blocks)
3. Create reference event,
apply boundary conditions
4. List trends, tendencies, constraints
5. Identify key uncertainties

30. 6. Use systems approach to create outcomes
7. Assess consistency and plausibility
8. Use numerical modelling where possible
9. Evaluate key uncertainties in the scenario
10. Turn scenario into an operational
decision-making tool for stakeholders

31. Conclusions
• scenario modelling is a technique for elucidating
situations in the face of uncontrollable, irreducible
uncertainty
• scenarios must strike a balance between
continuity and surprise
• scenarios involve a range of possible outcomes
- the envelope of uncertainty

32. Conclusions
• 'chunking': aggregation of small quanta of
knowledge into meaningful assemblages
• 'hedging': to limit or qualify by introducing
conditions or exceptions
• scenarios are more flexible than forecasts

33. Prof. David E. Alexander
david.alexander@ucl.ac.uk
emergency-planning.blogspot.com
www.slideshare.net/dealexander