Transcript Modeling Dependencies - Corps Risk Analysis Gateway

Scenarios for Uncertainty
Risk Analysis for Water Resources
Planning and Management
Institute for Water Resources
2008
Uncertainties
Average house value
Hurricane track
Forward speed of storm
Footprint of project
Sea level rise
Channel depth
Budgets and funding
Mean stream flow
Mean day percent of
shade
Cost/yd. concrete
Land use patterns/rates
Redevelopment rate in
NOLA
Landscape Scale Studies
Global importance
Affect millions of people
Great variety of wickedly complex problems
Major uncertainties common
Many possible futures
Examples
LaCPR
MsCIP
Upper Mississippi and Tributaries
Muskingum Watershed Conservancy District
Puget Sound
Columbia River
Coastal Louisiana
Everglades
When One Is Not Enough
Single most likely without project condition exists
Traditional planning approach
Address quantity and model uncertainty within that
scenario
More than one possible future and they are
significantly different
Scenario planning
Probabilistic scenario analysis
When to Use Scenario Planning
Consequence
Grave
Scenario Planning
Uncertainty
Deterministic Planning
Little
Much
Deterministic Planning
Standard Decision
Making
Minor
Scenario Planning Is Consistent
With P&G
It is not an alternative to
P&G
It is an enhancement for
situations with
significantly different
futures possible
Scenario planning
modifies tasks in some
steps
Traditional P&G Planning
It’s largely deterministic
Process relies on a single most likely alternative
future forecast
Desire for single right answer
Often anchored in present
Adversarial--legitimate differences in views of
uncertain future
Forecasting & Comparing Criteria
With & Without
Option Comparison
Plan Effects
Baseline Risk
Before & After
Comparison
Existing Risk
Target
Gap Analysis
Time
Most Likely Future Condition
We labor in uncertainty
A single forecast of the future will be wrong
Thus, planning is based on what could be not
necessarily what will be
What could be is wide open to debate
We cannot ignore it
The consequences of being wrong may be serious
Scenario Planning
Developed in second half of 20th century
(Europe)
Result of failure of traditional planning
Deterministic view of future
Forecasts were wrong
Barrow Coastal Problem
Even small projects can be complex!
Barrow’s Coast
Change
Storms and erosion
Global warming
Less ice cover-major
issue
Social & economic
infrastructure
Cultural consequences
Ivu
Severe
Goodbye Barrow
Consequence for
Quality of life
Troubled Times
Minor
Severe
Erosion rate&
Beach recovery
Happy Days
Surviving
Minor
What Scenarios Are
Narratives of alternative environments in which
today’s decisions may be played out
Neither predictions nor strategies
Hypotheses of different futures specifically
designed to highlight the risks and opportunities
involved in problem solving
Steps to Scenarios
1)
2)
3)
4)
5)
6)
Scenario team
Decision focus
Brainstorm a list of key factors
Distinguish pre-determined elements from
uncertainties
Identifying a few scenario logics
Flesh out scenarios
Scenario Team
Participants carefully recruited to include people
with
Thorough knowledge of the problem
Diverse backgrounds

Range of levels of management, perspectives, and roles
Variety of intellectual disciplines
Decision Focus
Identify key decision
Develop useful questions to ask about the decision
To be useful scenarios must teach relevant lessons to
decision makers

Must speak to decisions or direct concerns
Define time frame of scenario
Affects range of movement and creativity within scenario
Brainstorm Key Factors
No idea is evaluated at first
Identify driving forces and key trends
The most significant elements in external environment
Consider 5 general categories that interact to create complex, interesting
plots
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Social
Technological
Economic
Environmental
Political forces.
Each study must compile its own driving forces and key trends
What Are We Looking For?
Which key forces seem inevitable or pre-determined?
Trends unlikely to vary significantly in any scenario should be
reflected, implicitly or explicitly, in each scenario
Which forces are most likely to define or significantly
change the nature or direction of the scenarios?
Measured by two criteria
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
How uncertain are you of its outcome?
How important is it to solving your problem(s)?
Scenarios address things that are both very important and
very uncertain
How Can I Construct Scenarios
Deductive approach
Prioritize list of key factors
Construct a 2 x 2 scenario matrix based on 2 most
critical uncertainties

One method each participant gets 25 points to assign to
different the forces on the list
How Do We Flesh Out Scenarios?
Consider Systems and Patterns: Systems Thinking
Studying the way the parts of a system interact
Useful to map out events, patterns, and structure individually
then create systems diagrams together
Build Narratives
Once basic logics of different worlds are determined, weave
pieces together to form a narrative
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Beginning
Middle
End
How could we get from present to this new scenario? What
events are necessary?
Flesh Out Scenarios (cont.)
Identify characters to tell story around
Individuals, stakeholders or institutions that espouse
specific changes
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Known (real)
Invented (hypothetical)
May be driving forces
May crystallize logic of scenario
Typical Plots
Each scenario should be different, yet relevant to
focal question
Some archetypical plot lines arise regularly
Common Plots
Winners & losers
Crisis & response
Good news/bad news
Evolutionary change
Revolution
Tectonic Change
Cycles
Infinite Possibility
The Lone Ranger
Generations
Perpetual Transition
Tips for Scenarios
1.
2.
3.
4.
Stay Focused
Keep It Simple
Keep It Interactive
Plan to Plan and Allow
Enough Time
5. Don’t Settle for a Simple
High, Medium, and Low
6. Avoid Probabilities or “Most
Likely” Plots
7.
8.
9.
10.
Avoid Drafting Too Many
Scenarios
Invent Catchy Names for
the Scenarios
Make the Decision Makers
Own the Scenarios
Budget Sufficient Resources
for Communicating the
Scenarios
Then What?
Identify future scenarios
Do analysis
(good science)
Evaluate plans against all
scenarios
Heavy
Choose most robust plan
Wetter
Runoff
Light
P-loading
Dryer
Two Basic Ways to Proceed
Evaluate each plan against each of the four
scenarios (e.g., using MCDA results)
Results of this evaluation are compared across
plans to select a plan
Which plan does best (robustness) regardless of
the future realized?
Two Basic Ways to Proceed
Choose one of the four scenarios as most likely
Proceed as usual through the selection process
Evaluate the recommended plan against the other three
remaining scenarios
Unacceptable results in any scenario
Adaptive management
Reformulate
Another plan is selected
Who’s Doing It?
Industry
Europe
COE
Take Away Points
Landscape scale problems complex & diverse
Uncertainty is everywhere
Scenario planning to address uncertainty
MCDA needed to address complexity & collaborative
planning initiative
Scenario analysis--MCDA in scenario planning context
is a potential solution
What’s the Without Condition?
It is critical to plan formulation
It is critical to plan evaluation
It is a source of adversarial processes
See Washington Post vs. COE--Upper Miss
And you do not know what it is!