© k.fedra 20004 1 dimensions …… mediterranean: mediterranean: 3.7 10 6 km3 or 3.7 10 18 ltr...

© K.Fedra 200042

Decision Support SystemsDecision Support SystemsDecision Support SystemsDecision Support Systems

an introduction to DSS with an introduction to DSS with environmental application environmental application

examplesexamples

an introduction to DSS with an introduction to DSS with environmental application environmental application

examplesexamples

© K.Fedra 200043

What is a DSS ?What is a DSS ?What is a DSS ?What is a DSS ?

• Attempts at definitionAttempts at definition

• Decision making processesDecision making processes

• A general DSS architectureA general DSS architecture

• Decision Support ParadigmsDecision Support Paradigms

• Application examplesApplication examples


• Decision making processesDecision making processes

• A general DSS architectureA general DSS architecture



© K.Fedra 200044

DSS DefinitionDSS DefinitionDSS DefinitionDSS Definition

A DSS is a computer based A DSS is a computer based

problem solving system that problem solving system that

assists assists choicechoice between between

alternativesalternatives in complex and in complex and

controversial domains.controversial domains.

A DSS is a computer based A DSS is a computer based

problem solving system that problem solving system that

assists assists choicechoice between between

alternativesalternatives in complex and in complex and

controversial domains.controversial domains.

© K.Fedra 200045


Problem solving:Problem solving:

Problem:Problem: when the observed or perceived when the observed or perceived

(expected) state of a system differs from the (expected) state of a system differs from the

expectations, norms, goals.expectations, norms, goals.

If the expectation is optimisation (maximisation, If the expectation is optimisation (maximisation,

growth) we always have a problem (more than growth) we always have a problem (more than

yesterday, more than others)yesterday, more than others)

Problem solving:Problem solving:

Problem:Problem: when the observed or perceived when the observed or perceived

(expected) state of a system differs from the (expected) state of a system differs from the

expectations, norms, goals.expectations, norms, goals.

If the expectation is optimisation (maximisation, If the expectation is optimisation (maximisation,

growth) we always have a problem (more than growth) we always have a problem (more than

yesterday, more than others)yesterday, more than others)

© K.Fedra 200046


A DSS provides A DSS provides • structured presentation structured presentation • problem context, problem context, • and tools for theand tools for the

– design, – evaluation,– selection

of alternativesof alternatives

A DSS provides A DSS provides • structured presentation structured presentation • problem context, problem context, • and tools for theand tools for the

– design, – evaluation,– selection

of alternativesof alternatives

© K.Fedra 200047

What is a DSS ?What is a DSS ?What is a DSS ?What is a DSS ?


• Decision making processesDecision making processes• A general DSS architectureA general DSS architecture




• Decision making processesDecision making processes• A general DSS architectureA general DSS architecture



© K.Fedra 200048

Decision making processesDecision making processesDecision making processesDecision making processes

Handbook of ORHandbook of OR (B.E.Gillet, 1976):(B.E.Gillet, 1976):

• Formulation of the problemFormulation of the problem• Construction of a mathematical modelConstruction of a mathematical model• Derive solution from modelDerive solution from model• Testing model and solutionTesting model and solution• Establish control over the solutionEstablish control over the solution• Put it to work (implementation)Put it to work (implementation)

Handbook of ORHandbook of OR (B.E.Gillet, 1976):(B.E.Gillet, 1976):

• Formulation of the problemFormulation of the problem• Construction of a mathematical modelConstruction of a mathematical model• Derive solution from modelDerive solution from model• Testing model and solutionTesting model and solution• Establish control over the solutionEstablish control over the solution• Put it to work (implementation)Put it to work (implementation)

© K.Fedra 200049


HeuristicsHeuristics (How to solve it, G.Polya)(How to solve it, G.Polya)

• understand the problemunderstand the problem

• make a plan (algorithm)make a plan (algorithm)

• implement step by stepimplement step by step

• check each stepcheck each step

• check the solution (looking back)check the solution (looking back)

HeuristicsHeuristics (How to solve it, G.Polya)(How to solve it, G.Polya)

• understand the problemunderstand the problem

• make a plan (algorithm)make a plan (algorithm)

• implement step by stepimplement step by step

• check each stepcheck each step

• check the solution (looking back)check the solution (looking back)

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(in the real world)(in the real world) are characterized by: are characterized by:

• multiple actorsmultiple actors

• uncertaintyuncertainty

• conflicting objectivesconflicting objectives

• multiple criteriamultiple criteria

• plural rationalitiesplural rationalities

• hidden agendahidden agenda

(in the real world)(in the real world) are characterized by: are characterized by:







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are characterized by:are characterized by:














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multiple actors:multiple actors:multiple actors:multiple actors:• researchers and analystsresearchers and analysts• planners and managersplanners and managers• policy and decision makerspolicy and decision makers• general public:general public:

• consumers (market)consumers (market)• concerned citizen (voters)concerned citizen (voters)

• researchers and analystsresearchers and analysts• planners and managersplanners and managers• policy and decision makerspolicy and decision makers• general public:general public:

• consumers (market)consumers (market)• concerned citizen (voters)concerned citizen (voters)

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Uncertainty:Uncertainty:

All elements are “uncertain”:All elements are “uncertain”:

• Criteria, Criteria,

• Objectives, Objectives,

• ConstraintsConstraints

Uncertainty:Uncertainty:

All elements are “uncertain”:All elements are “uncertain”:

• Criteria, Criteria,

• Objectives, Objectives,

• ConstraintsConstraints

© K.Fedra 2000416


conflicting objectives:conflicting objectives:• maximize economic benefits maximize economic benefits • minimize environmental costsminimize environmental costs• maximize environmental benefitsmaximize environmental benefits• minimize economic costsminimize economic costs• maintain equitymaintain equity::

• between social groupsbetween social groups• between regions and countriesbetween regions and countries• between generationsbetween generationsSUSTAINABILITYSUSTAINABILITY

• maximize economic benefits maximize economic benefits • minimize environmental costsminimize environmental costs• maximize environmental benefitsmaximize environmental benefits• minimize economic costsminimize economic costs• maintain equitymaintain equity::

• between social groupsbetween social groups• between regions and countriesbetween regions and countries• between generationsbetween generationsSUSTAINABILITYSUSTAINABILITY

© K.Fedra 2000418


multiple criteria:multiple criteria:• economic criteria economic criteria (costs)(costs)

• environmental criteriaenvironmental criteria• standards standards (measurements)(measurements)

• perceptions perceptions (believes, fears)(believes, fears)

• political criteria political criteria (equity)(equity)

• regulatory criteria regulatory criteria (constraints)(constraints)

• technological criteria technological criteria (constraints)(constraints)

• economic criteria economic criteria (costs)(costs)

• environmental criteriaenvironmental criteria• standards standards (measurements)(measurements)

• perceptions perceptions (believes, fears)(believes, fears)

• political criteria political criteria (equity)(equity)

• regulatory criteria regulatory criteria (constraints)(constraints)

• technological criteria technological criteria (constraints)(constraints)

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plural rationalitiesplural rationalities

rationalrational: relating to, based on, : relating to, based on, agreeable to agreeable to reasonreason. .

reason: the power of inferring, reason: the power of inferring, comprehending, or thinking in an comprehending, or thinking in an orderly, orderly, rational rational way.way.


rationalrational: relating to, based on, : relating to, based on, agreeable to agreeable to reasonreason. .

reason: the power of inferring, reason: the power of inferring, comprehending, or thinking in an comprehending, or thinking in an orderly, orderly, rational rational way.way.

© K.Fedra 2000421



rationalrational: L. : L. ratio (reor, reri, ratus)ratio (reor, reri, ratus)

computation, advantage, interest,computation, advantage, interest,

behavior, procedure, ways and means, behavior, procedure, ways and means, motivation, argument, proof, opinion, motivation, argument, proof, opinion, (scientific) theory.(scientific) theory.


rationalrational: L. : L. ratio (reor, reri, ratus)ratio (reor, reri, ratus)

computation, advantage, interest,computation, advantage, interest,

behavior, procedure, ways and means, behavior, procedure, ways and means, motivation, argument, proof, opinion, motivation, argument, proof, opinion, (scientific) theory.(scientific) theory.

© K.Fedra 2000422



reaching different (contradictory) reaching different (contradictory) conclusions from the same set of conclusions from the same set of premises in an internally consistent premises in an internally consistent logical way.logical way.


reaching different (contradictory) reaching different (contradictory) conclusions from the same set of conclusions from the same set of premises in an internally consistent premises in an internally consistent logical way.logical way.

© K.Fedra 2000424


Hidden agenda:Hidden agenda:Not all objectives of all actors are Not all objectives of all actors are

disclosed.disclosed.Proclaim one (popular) objective to Proclaim one (popular) objective to

reach another, different (and not reach another, different (and not disclosed, less popular or disclosed, less popular or acceptable) objective.acceptable) objective.

Hidden agenda:Hidden agenda:Not all objectives of all actors are Not all objectives of all actors are

disclosed.disclosed.Proclaim one (popular) objective to Proclaim one (popular) objective to

reach another, different (and not reach another, different (and not disclosed, less popular or disclosed, less popular or acceptable) objective.acceptable) objective.

© K.Fedra 2000425

A general DSS architectureA general DSS architectureA general DSS architectureA general DSS architecture

• Information resourcesInformation resources

• The analytical engineThe analytical engine

• The user interfaceThe user interface

• Information resourcesInformation resources

• The analytical engineThe analytical engine

• The user interfaceThe user interface

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Information ResourcesInformation ResourcesInformation ResourcesInformation Resources

• information on the information on the status-quo status-quo (monitoring)(monitoring)

• background for the background for the identification or designidentification or design of decision alternativesof decision alternatives

• information on the information on the status-quo status-quo (monitoring)(monitoring)

• background for the background for the identification or designidentification or design of decision alternativesof decision alternatives

© K.Fedra 2000427

The analytical engineThe analytical engineThe analytical engineThe analytical engine

• Data base management systemData base management system

• Geographic Information SystemGeographic Information System

• Simulation and optimization modelsSimulation and optimization models

• Expert systems (rules)Expert systems (rules)

• Decision Support tools Decision Support tools properproper

• Data base management systemData base management system

• Geographic Information SystemGeographic Information System

• Simulation and optimization modelsSimulation and optimization models

• Expert systems (rules)Expert systems (rules)

• Decision Support tools Decision Support tools properproper

© K.Fedra 2000428

The User InterfaceThe User InterfaceThe User InterfaceThe User Interface• interactive, dialogue oriented, menu interactive, dialogue oriented, menu

driven, intuitive, graphical, symbolicdriven, intuitive, graphical, symbolic• consistent syntax and semantics, consistent syntax and semantics,

layout and symbolism, intelligent, layout and symbolism, intelligent, context aware, customizedcontext aware, customized

• also includes organizational issues also includes organizational issues (e.g., for workshops, presentations, (e.g., for workshops, presentations, hearings) group dynamics, hearings) group dynamics, communicationcommunication

ALL SCIENCE IS PROPAGANDAALL SCIENCE IS PROPAGANDA (P.Feyerabend) (P.Feyerabend)

• interactive, dialogue oriented, menu interactive, dialogue oriented, menu driven, intuitive, graphical, symbolicdriven, intuitive, graphical, symbolic

• consistent syntax and semantics, consistent syntax and semantics, layout and symbolism, intelligent, layout and symbolism, intelligent, context aware, customizedcontext aware, customized

• also includes organizational issues also includes organizational issues (e.g., for workshops, presentations, (e.g., for workshops, presentations, hearings) group dynamics, hearings) group dynamics, communicationcommunication

ALL SCIENCE IS PROPAGANDAALL SCIENCE IS PROPAGANDA (P.Feyerabend) (P.Feyerabend)

© K.Fedra 2000429

Decision support paradigmsDecision support paradigmsDecision support paradigmsDecision support paradigms

• Information systemsInformation systems

• Scenario analysisScenario analysis

WHAT IFWHAT IF

• Rational maximizationRational maximization

HOW TOHOW TO

• Multiple attributesMultiple attributes



WHAT IFWHAT IF


HOW TOHOW TO


© K.Fedra 2000430




WHAT IFWHAT IF


HOW TOHOW TO




WHAT IFWHAT IF


HOW TOHOW TO


© K.Fedra 2000431

Information systemsInformation systemsInformation systemsInformation systems

• provide problem contextprovide problem context

• describe available alternativesdescribe available alternatives

• offer a common language and offer a common language and shared information basis for the shared information basis for the participants in the decision making participants in the decision making processprocess

• provide problem contextprovide problem context

• describe available alternativesdescribe available alternatives

• offer a common language and offer a common language and shared information basis for the shared information basis for the participants in the decision making participants in the decision making processprocess

© K.Fedra 2000432

Information systemsInformation systemsInformation systemsInformation systems

typical application example:typical application example:

State-of-the-Environment ReportingState-of-the-Environment Reporting

decision process usually diffuse, decision process usually diffuse, multi-stage and lengthy without multi-stage and lengthy without clear technical objectives.clear technical objectives.

Public information, awareness Public information, awareness building, assists argumentation.building, assists argumentation.


State-of-the-Environment ReportingState-of-the-Environment Reporting

decision process usually diffuse, decision process usually diffuse, multi-stage and lengthy without multi-stage and lengthy without clear technical objectives.clear technical objectives.

Public information, awareness Public information, awareness building, assists argumentation.building, assists argumentation.

© K.Fedra 2000433




WHAT IFWHAT IF


HOW TOHOW TO




WHAT IFWHAT IF


HOW TOHOW TO


© K.Fedra 2000434


Scenario analysisScenario analysisexplores the reaction of a system to explores the reaction of a system to

changes in the controlchanges in the control or decision or decision variables on the performance variables on the performance variables (criteria) in terms of the variables (criteria) in terms of the objectives and constraints of the objectives and constraints of the decision problem.decision problem.

Scenario analysisScenario analysisexplores the reaction of a system to explores the reaction of a system to

changes in the controlchanges in the control or decision or decision variables on the performance variables on the performance variables (criteria) in terms of the variables (criteria) in terms of the objectives and constraints of the objectives and constraints of the decision problem.decision problem.

© K.Fedra 2000435


Scenario Scenario from L. from L. scaenarium, scaenarium, the stagethe stage

an account or synopsis of a projected an account or synopsis of a projected

course of action or events;course of action or events;

a set of assumptions.a set of assumptions.

Scenario Scenario from L. from L. scaenarium, scaenarium, the stagethe stage

an account or synopsis of a projected an account or synopsis of a projected

course of action or events;course of action or events;

a set of assumptions.a set of assumptions.

© K.Fedra 2000436



Environmental Impact Environmental Impact AssessmentAssessment, that evaluates and , that evaluates and compares project alternatives.compares project alternatives.

Exploratory (policy) assessment, Exploratory (policy) assessment, design of alternatives.design of alternatives.


Environmental Impact Environmental Impact AssessmentAssessment, that evaluates and , that evaluates and compares project alternatives.compares project alternatives.

Exploratory (policy) assessment, Exploratory (policy) assessment, design of alternatives.design of alternatives.

© K.Fedra 2000437




WHAT IFWHAT IF


HOW TOHOW TO




WHAT IFWHAT IF


HOW TOHOW TO


© K.Fedra 2000438

Rational maximizationRational maximizationRational maximizationRational maximization

The individual as rational maximizerThe individual as rational maximizer

chooses a commodity bundle chooses a commodity bundle

c = (cc = (c11,...,c,...,cii,...,c,...,cn n ))

that maximizes the utilitythat maximizes the utility

u(c)u(c)

The individual as rational maximizerThe individual as rational maximizer

chooses a commodity bundle chooses a commodity bundle

c = (cc = (c11,...,c,...,cii,...,c,...,cn n ))

that maximizes the utilitythat maximizes the utility

u(c)u(c)

© K.Fedra 2000439


maximize the utility maximize the utility u(c)u(c)– over different groups over different groups ( i )( i )– over space over space (x,y,z)(x,y,z)– over time over time ( t )( t )

maximize the utility maximize the utility u(c)u(c)– over different groups over different groups ( i )( i )– over space over space (x,y,z)(x,y,z)– over time over time ( t )( t )

© K.Fedra 2000440


The social welfare functionThe social welfare function

u*(c) = f [uu*(c) = f [u11(c),u(c),u22(c),...,u(c),...,unn(c) ](c) ]

as the sum as the sum

iiuuii(c)(c)

of individual or group of individual or group

utility functions uutility functions uii(c)(c)

The social welfare functionThe social welfare function

u*(c) = f [uu*(c) = f [u11(c),u(c),u22(c),...,u(c),...,unn(c) ](c) ]

as the sum as the sum

iiuuii(c)(c)

of individual or group of individual or group

utility functions uutility functions uii(c)(c)

© K.Fedra 2000441

Rational choiceRational choiceRational choiceRational choice

LetLet (x,p,y) (x,p,y) denote an option where denote an option where

x x is obtained with probabilityis obtained with probability p p

yy is obtained with probability is obtained with probability 1-p 1-p

from: A.Tversky, (1977)from: A.Tversky, (1977)

On the elicitation of preferencesOn the elicitation of preferences.

LetLet (x,p,y) (x,p,y) denote an option where denote an option where

x x is obtained with probabilityis obtained with probability p p

yy is obtained with probability is obtained with probability 1-p 1-p

from: A.Tversky, (1977)from: A.Tversky, (1977)

On the elicitation of preferencesOn the elicitation of preferences.

© K.Fedra 2000442


Assume two alternatives of Assume two alternatives of emergency management:emergency management:

AA11 50:50 to lose 100 lives 50:50 to lose 100 lives

AA22 certain to lose 45 lives certain to lose 45 lives

You can execute AYou can execute A11 OR OR A A22

What do you choose ?What do you choose ?

Assume two alternatives of Assume two alternatives of emergency management:emergency management:



You can execute AYou can execute A11 OR OR A A22

What do you choose ?What do you choose ?

© K.Fedra 2000448


context dependence and bias:context dependence and bias:

certainty versus probabilitycertainty versus probability

gain versus lossgain versus loss

absolute versus relative changeabsolute versus relative change

context dependence and bias:context dependence and bias:

certainty versus probabilitycertainty versus probability

gain versus lossgain versus loss

absolute versus relative changeabsolute versus relative change

© K.Fedra 2000449

Decision makingDecision makingDecision makingDecision making

Minimax and Bayesian approaches:Minimax and Bayesian approaches:

Decision maker has:Decision maker has:

• a finite number of possible decision a finite number of possible decision alternativesalternatives

• a finite number of a finite number of outcomesoutcomes (state of nature) (state of nature)

which may have a known probability of outcomewhich may have a known probability of outcome

• a a cost or benefitcost or benefit for each decision - state-of- for each decision - state-of-

nature combinationnature combination

Minimax and Bayesian approaches:Minimax and Bayesian approaches:

Decision maker has:Decision maker has:

• a finite number of possible decision a finite number of possible decision alternativesalternatives

• a finite number of a finite number of outcomesoutcomes (state of nature) (state of nature)

which may have a known probability of outcomewhich may have a known probability of outcome

• a a cost or benefitcost or benefit for each decision - state-of- for each decision - state-of-

nature combinationnature combination

© K.Fedra 2000450


Decision Table:Decision Table:

State of NatureState of Nature

DecisionDecision rain no-rainrain no-rain

take a raincoattake a raincoat 0 0 3 3

no raincoatno raincoat 6 6 0 0(0, 3, 6, are the associated costs)(0, 3, 6, are the associated costs)

What do you do ?What do you do ?




take a raincoattake a raincoat 0 0 3 3

no raincoatno raincoat 6 6 0 0(0, 3, 6, are the associated costs)(0, 3, 6, are the associated costs)

What do you do ?What do you do ?

© K.Fedra 2000451





take a raincoattake a raincoat 0 0 3 3 ((33))

no raincoatno raincoat 6 6 0 0 (6)(6)

Minimax Solution (conservative):Minimax Solution (conservative):

take a raincoat !take a raincoat !




take a raincoattake a raincoat 0 0 3 3 ((33))

no raincoatno raincoat 6 6 0 0 (6)(6)

Minimax Solution (conservative):Minimax Solution (conservative):

take a raincoat !take a raincoat !

© K.Fedra 2000452


Decision Table: Decision Table: (with added probabilities)(with added probabilities)


DecisionDecision rain rain (0.1)(0.1) no-rain no-rain (0.9)(0.9)

take a raincoattake a raincoat 0 (0) 0 (0) 3 3 (2.7)(2.7) (2.7)(2.7)

no raincoatno raincoat 6 (0.6) 6 (0.6) 0 0 (0) (0) ((0.60.6))

Bayesian Solution:Bayesian Solution:

don’t take a raincoat !don’t take a raincoat !

Decision Table: Decision Table: (with added probabilities)(with added probabilities)


DecisionDecision rain rain (0.1)(0.1) no-rain no-rain (0.9)(0.9)

take a raincoattake a raincoat 0 (0) 0 (0) 3 3 (2.7)(2.7) (2.7)(2.7)

no raincoatno raincoat 6 (0.6) 6 (0.6) 0 0 (0) (0) ((0.60.6))

Bayesian Solution:Bayesian Solution:

don’t take a raincoat !don’t take a raincoat !

© K.Fedra 2000453



States of NatureStates of Nature

DecisionDecision rain rain (0.1)(0.1) little little (0.5)(0.5) none none (0.4)(0.4)

take a raincoattake a raincoat 0 (0) 0 (0) 0 (0) 3 (1.2) 0 (0) 3 (1.2)

no raincoatno raincoat 6 (0.6) 1 (0.5) 0 (0) 6 (0.6) 1 (0.5) 0 (0)

And now ?And now ?




take a raincoattake a raincoat 0 (0) 0 (0) 0 (0) 3 (1.2) 0 (0) 3 (1.2)

no raincoatno raincoat 6 (0.6) 1 (0.5) 0 (0) 6 (0.6) 1 (0.5) 0 (0)

And now ?And now ?

© K.Fedra 2000454





take a raincoattake a raincoat 0 (0) 0 (0) 0 (0) 0 (0) 33 (1.2) (1.2) 1.21.2

no raincoatno raincoat 66 (0.6) 1 (0.5) 0 (0) (0.6) 1 (0.5) 0 (0) 1.11.1

MiniMaxMiniMax: : take a raincoat take a raincoat

BayesianBayesian:: take no raincoat take no raincoat




take a raincoattake a raincoat 0 (0) 0 (0) 0 (0) 0 (0) 33 (1.2) (1.2) 1.21.2

no raincoatno raincoat 66 (0.6) 1 (0.5) 0 (0) (0.6) 1 (0.5) 0 (0) 1.11.1

MiniMaxMiniMax: : take a raincoat take a raincoat

BayesianBayesian:: take no raincoat take no raincoat

© K.Fedra 2000456


Multiple attributesMultiple attributes

multiple objectivesmultiple objectives

multiple criteriamultiple criteria

trade-off, compromise, trade-off, compromise,

satisfaction, acceptancesatisfaction, acceptance

Multiple attributesMultiple attributes

multiple objectivesmultiple objectives

multiple criteriamultiple criteria

trade-off, compromise, trade-off, compromise,

satisfaction, acceptancesatisfaction, acceptance

© K.Fedra 2000457

Decision making processDecision making processDecision making processDecision making process

• Problem descriptionProblem description

• Set of criteriaSet of criteria– objectives– constraints

• Set of feasible alternativesSet of feasible alternatives

• Evaluation of alternativesEvaluation of alternatives

• Decision rulesDecision rules

• Problem descriptionProblem description

• Set of criteriaSet of criteria– objectives– constraints

• Set of feasible alternativesSet of feasible alternatives

• Evaluation of alternativesEvaluation of alternatives

• Decision rulesDecision rules

© K.Fedra 2000458

Decision making processDecision making processDecision making processDecision making process

SpatialSpatial decisions: decisions:

• Set of Set of criteriacriteria– objectives

– constraints

areare functions of spacefunctions of space

SpatialSpatial decisions: decisions:

• Set of Set of criteriacriteria– objectives

– constraints

areare functions of spacefunctions of space

© K.Fedra 2000459

Spatial decisionsSpatial decisionsSpatial decisionsSpatial decisions

Environmental decision are also Environmental decision are also spatial decisionsspatial decisions::

• site selection, locationsite selection, location

• pollution controlpollution control

• natural resources managementnatural resources management

• environmental impact assessmentenvironmental impact assessment

• risk analysis and managementrisk analysis and management

Environmental decision are also Environmental decision are also spatial decisionsspatial decisions::

• site selection, locationsite selection, location

• pollution controlpollution control

• natural resources managementnatural resources management

• environmental impact assessmentenvironmental impact assessment

• risk analysis and managementrisk analysis and management

© k.fedra 20004 1 dimensions …… mediterranean: mediterranean: 3.7 10 6 km3 or 3.7 10 18 ltr...

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