Evaluate Alternatives Evaluate Alternatives

OverviewOverview

In this section we will discuss the selection among alternatives

The roles of analysts and decision makers

Trade-studies

Functions, requirements, and architecture

Multi-objective decision making

Reaching consensus

The Process of Selecting a StrategyThe Process of Selecting a Strategy

We now have developed alternatives, we must

Select the best Discard the inappropriate Sustain other potential alternatives Provide decision makers with guidance in their

selection

Always consider our planning opportunities, objectives, and constraints.

Conflict Between Roles of Analyst and Decision Maker

Conflict Between Roles of Analyst and Decision Maker

A skilled analyst incorporates preferences into an analysis

A skilled decision maker recognizes that factors outside of the analysis may also be important

Analystexplorationvariationsensitivity

trade studies

Decision Makerpolitical realities

acceptabilitychanges in public perception

legislation

Words of WisdomWords of Wisdom

Although we identified alternatives we still need a top-down approach in the selection process,

Screening Selection Analysis

With increasing attention to: Completeness Effectiveness Acceptability Efficiency

Overview of the Selection ProcessOverview of the Selection Process

Compare alternatives Analytical Subjective

Rank alternatives

Seek consensus

Modify alternatives to address concerns

Adopt an alternative

In all phases of this process, both quantitative and subjective information must be included.

Trade StudiesTrade Studies

Within the aerospace industry, this analytical process is termed “trade studies”

Derived from trade-off analysis

Parametrically explore response of system to changes in input or transformations

Develop surface response curves

Emphasis on life cycle

Functions, Requirements, Architecture and Testing

Functions, Requirements, Architecture and Testing

Problems became more complex and... Engineering specialization led to difficulties Need for common information and database No individual could track entire process Coordination and system management became

essential

Systems Engineering emerged and...

Functions, Requirements, Architecture and Testing (FRAT)

FRATFRAT

1. Define the system boundaries, inputs and outputs

2. Define what the system must do (Functions)

3. Define how well these functions must be performed (Requirements)

4. Identify and evaluate multiple alternatives

5. Define the best answers (Architecture)

6. Perform tests to ensure system performance

ComparisonsComparisons

There is a clear relationship between water resources planning and FRAT methodology

Major difference is FRAT’s emphasis on structured approach

Divide complex problem into sub-problems

Define functional relationships between sub-problems

Identify life cycle costs

Multi-Objective Programming (MOP) and Planning

Multi-Objective Programming (MOP) and Planning

MOP Recognizes that “real world” problems contain

multiple, conflicting objectives Maximize system reliability, minimize

environmental impacts, maximize power production

Maintains metrics of performance in “appropriate, natural and descriptive” units - unlike dollars

Facilitates the generation of objective function trade-off curves

Decision Making Context

Single Decision Makeror Decision Group

Multi-Objective Solution Methods

Bottom-UpInformation Flow

Generating Techniques

Top-DownInformation Flow

Techniques thatIncorporate Preferences

Conflict Resolution

Multiple DecisionMaker Methods

Classifications of MOP ApproachesClassifications of MOP Approaches

MOP FormulationMOP Formulation

In water resources, most MOP problem formulations are optimizations:

Max Z(x1,x2.....xn)

such that gi(x1,x2,....xn)<=0

xj>0

Where Z’s are a vector of multiple objectives and X’s are decision variables

Within water resources literature, most formulations are linear programs.

Non InferiorityNon Inferiority

“A solution to MOP is non-inferior if there exists no other solution that will yield an improvement in one objective without causing a degradation in at least one other objective.”

MaximizePower

Environmental Quality

Correspondence exists between feasible region in decision space and the feasible region in objective space.

Size of InstalledTurbine

Minimum Instream Fish Flow, in 1000 cfs1 2 3 4 5 6

5

10

15

20

25

30

5 10 15 20 25 30 35

Power Production

Environmental Quality

Classifications of MOP ApproachesClassifications of MOP Approaches

Decision Making Context

Single Decision Makeror Decision Group

Multi-Objective Solution Methods

Bottom-UpInformation Flow

Generating Techniques

Top-DownInformation Flow

Techniques thatIncorporate Preferences

Conflict Resolution

Multiple DecisionMaker Methods

Generating TechniquesGenerating Techniques

Develop information about a problem allowing the range of choice and trade-offs among objectives to be understood

This is a combination of further analysis and selection among alternatives

Goal is generation and evaluation of alternatives in terms of objectives

Goal is not political analysis or prediction

Examples Weighting method Constraint method NISE

Preference TechniquesPreference Techniques

Require decision makers to articulate their preferences

Goal is to incorporate the decision maker’s preference into analytical framework

Once articulated, the preferences help define non-inferior region

Examples Prior assessment of weights Goal programming Surrogate worth trade-off method

Analytical Hierarchy MethodAnalytical Hierarchy Method

Method widely introduced by Thomas L. Saaty

Requires hierarchical organization of problem

Performed by comparing activities at different levels

Uses pair-wise comparisons

An Example:An Example:

Purchase a Car

Cost Comfort Reliability Power

Rabbit Subaru Wagon Jaguar

The ScaleThe Scale

With respect to Cost, compare alternatives Rabbit and Subaru

Score Meaning1/9 A is absolutely less important than B

1/7 A is demonstrably or very strongly less important than B

1/5 A is less important than B

1/3 A is weakly less important than B

1 A and B are equally important

3 A is weakly more important than B

5 A is more important than B

7 A is demonstrably or very strongly more important than

9 A is absolutely more important than B

The Process of AHPThe Process of AHP

Pair-wise comparison matrices are generated at each level

The eigen value is taken of each matrix for a final ranking of alternatives at each level

Measures of consistency are generated

Reaching ConsensusReaching Consensus

Bring scoping and evaluation process to closure Select a strategy Implement a plan

What is required to accomplish these goals? Plans must be perceived as fair, feasible, and

implementable Consensus is a key element in these outcomes

Different Paths to Agreement (Lamb 1990)Different Paths to Agreement (Lamb 1990)

Competitive - “a hard competitive strategy characterized by martial tactics & grudging reluctance to compromise”

Cooperative - a “cooperative strategy of give and take, aimed at learning the weakness of the other side”

Integrative - “a principled negotiation

Creating Consensus RequiresCreating Consensus Requires

Communication

Cooperation

Compromise

Incentive

The DPS Planning Process builds consensus throughout plan development

Plan Development & Consensus Building: A Common Path

Plan Development & Consensus Building: A Common Path

Consensus Building Process Planning Process Pre-Negotiation Phase

• Getting started • Assemble a team

• Representation • Identify problems and

• Drafting protocols establish planning

& setting the agenda objectives

• Joint fact-finding • Define the status quo

Consensus Building Process Planning Process Negotiation Phase

• Inventing options for • Formulate alternatives

mutual gain • Evaluate alternatives and

• Packaging agreements select strategy

• Producing a written

agreement

• Binding the parties to

their agreements

• Ratification

Plan Development & Consensus Building: A Common Path

Plan Development & Consensus Building: A Common Path

Plan Development & Consensus Building: A Common Path

Plan Development & Consensus Building: A Common Path

Consensus Building Process Planning Process Implementation orPost-Negotiation Phase

• Linking informal • Implement plan

agreements to formal • Maintain & exercise plan

decision making

• Monitoring

• Creating a context

for renegotiations

Tips From The Experts... Getting to Yes (Fisher & Ury 1991)

Tips From The Experts... Getting to Yes (Fisher & Ury 1991)

Separate the people from the problem

Focus on interests not positions

Invent options for mutual gain

Insist on using objective criteria

Tips From The Experts... Moving Towards Closure (Cormick 1987)

Tips From The Experts... Moving Towards Closure (Cormick 1987)

1. Start with a range of alternatives

2. Periodically summarize areas of agreement and disagreement

3. Recognize movement, even wrapped in strange ways

4. Have a strategy when dealing with boulders on the road

5. Build big agreements on small agreements

6. Look for packages

7. Look for mutual benefits - expand the pie

8. Use the deadline

Tips From The Experts... Obstacles to Consensus

Tips From The Experts... Obstacles to Consensus

Perceptions of inequity

Unmet interests

Fear of losing face

Impending deadlines

Tips From The Experts... Getting Past No (Ury & Fisher)

Tips From The Experts... Getting Past No (Ury & Fisher)

Step 1. Don’t react, go to the balcony

Step 2. Disarm them, step to their side

Step 3. Change the game - don’t reject...reframe

Step 4. Build a golden bridge

Step 5. Make it hard to say no

When There Is Not ConsensusWhen There Is Not Consensus

Conclude the discussions

Identify areas where participants “agreed to disagree”

Emphasize what was achieved

A Final Step to Plan SelectionA Final Step to Plan Selection

Produce a written agreement to

Ensure that the parties have heard and understood each other

Provide something concrete for representatives to take back to their members for review and ratification

The “Single Text” ProcedureThe “Single Text” Procedure

A draft is created by an individual or working group

Participants review and modify the document until closure is reached

The text is viewed as a working draft throughout this process

Participants are asked to improve rather than criticize

SummarySummary

Numerous techniques exist for alternative evaluation

Multiobjective programming offers range of approaches

AHP provides techniques to incorporate subjective information

Consensus building is essential step in alternative selection

ExerciseExercise