GROUP DECISION MAKING
UNDER MULTIPLE CRITERIA
Introduction
Özgür Kabak
E-mail:
­ [email protected]
­ [email protected]
Tel.: 0212 2931300 / 2039
Office Address: ITU İşletme Fakültesi A311
Who am I?
Özgür Kabak, PhD.
­ Associate Professor
­ Industrial Engineering Dept. of Istanbul Technical University (ITU)
­ Ph.D. from ITU (2008)
­ Modeling supply chain network using possibilistic linear programming and an application
­ Postdoc at Belgium Nuclear Research Centre (SCK.CEN), Mol, Belgium
­ Feb. 2009 – Feb. 2010
­ A fuzzy multiple attribute decision-making approach for nuclear safeguards information
management
­ Researh Interest
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Operations Research - Mathematical Programming
Fuzzy Decision Making
Transportation research
Group Decision Making
Modeling Complex systems
Course Description
To introduce the students to various methods of enhancing creativity and
group decision-making under multiple criteria
To analyse the various phases and stages of group decision making
To integrate the theory and practice through articles based on the real life
application of the GDM methods
Course Objectives
1.
To analyze the differences of individual versus group decision making
techniques
2.
To teach when to use a group decision making approach
3.
To teach different group decision making techniques under multiple
criteria
4.
To see their basic drawbacks, similarities and differences between the
group decision making techniques.
Course Learning Outcomes
1.
They learn when to use which type (individual versus group) of decision
making approach
2.
When the criteria are implicitly defined, being aware of Arrow’s
Impossibility theory, they learn how to investigate which voting method will
be closer to true group decision making and the basic drawbacks that can
be encountered
3.
When the criteria are explicitly defined, they can reduce their data set
and criteria through data mining techniques
4.
They know when to use which group decision making method and
understand its advantages and disadvantages
5.
To know the real world applications and success of the methods
Webpage: http://ninova.itu.edu.tr/Ders/4574
Most of the references related to the course are journal papers. Please see
the web page for the list of selected papers.
References
­ Hwang, C.L. and Lin, M.J.(1987), «Group Decision Making under Multiple Criteria», Lecture
Notes in Economics and Mathematical Systems, Springer-Verlag, Berlin
­ Tzeng, G.H., Huang, J.J. (2011), «Multiple Attribute Decision Making», CRC Press, Taylor &
Francis Group, NW
­ Lu, J., Zhang, G., Ruan, D., Wu, F. (2007) «Multi-Objective Group Decision Making», Imperial
College Press,
­ Brams, S., (2008) «Mathematics and Democracy: Designing Better Voting and Fair -Dvision
Procedures», Princeton University Press, Princeton, New Jersey
­ Kabak, Ö., Ervural, B. (2017) Multiple Attribute Group Decision Making: A generic conceptual
framework and a classification scheme, Knowledge-based Systems, Accepted.
Schedule (tentative)
Week Date
Topic
1
09/02/2017 Introduction to Group Decision making
2
16/02/2017 Social Choice Theory
3
23/02/2017 Social Choice Theory (cont.)
4
02/03/2017 Cook & Seiford’s Ordinal Intersection Method, N-Head Analysis
5
09/03/2017 Presentations of the 1st group of papers
6
16/03/2017 Process-oriented approaches
7
23/03/2017 Multiple Attribute Decision Making
30/03/2017 SPRING BREAK
8
06/04/2017 Group Decision Making with Explicit Multi Attribute Evaluation
9
13/04/2017 Presentations of the 2nd group of papers
10
20/04/2017 Midterm Exam
11
27/04/2017 Fuzzy Set theory based GDM Methods
12
04/05/2017 Cumulative Belief Degrees Approach for GDM
13
11/05/2017 Linguistic Evaluation & Consensus Measures
14
18/05/2017 Presentations of the 2nd group of papers
Group Presentations
You will be responsible for presenting the following topics based on
distributed papers.
Each group will be responsible for 4-5 papers.
Each student will be in two groups. I will randomly assign the students to the
groups!
Topics
­ Implicit Multiattribute Evaluation (March, 9)
­ Explicit Multiattribute Evaluation – Classical methods (April, 13)
­ Explicit Multiattribute Evaluation – New trends (May, 18)
Assignments
Homework assignments will be given to get prepared for the classes and to
practice the given theory.
You will be given 5-6 homework assignments:
Each assignment will be announced one or two weeks before the submission
deadline during the class.
No quiz!
Class Participation
­ Students are expected and encouraged to participate the class through
questions, statements, and comments.
­ It is the quality of these contributions that is more important than the
quantity.
Attendance
­ Attendance is mandatory and will be checked for each class.
­ Students having less than 70% attendance will be given VF as a final
grade.
Grading
Paper presentation (25%)
Assignments (15%)
Midterm exam (20%)
Final exam (40%)
Participation (+ up to 10 extra points)
You have to get at least 50 from the paper presentation and at least 50 from
the assignments to participate in the Final Exam. Otherwise you will be given
VF.
Cheating and plagiarism
Do not.
Studying together to understand the material is fine, but the work you hand in
is to be your own.
You have to refer the references you used and paraphrase the sentences you
refer.
No cheating will be tolerated: A letter grade of VF will be given!
Class Sessions
(tentative)
There will be two sessions every week on Thursday.
13:30 – 14:50
1st session
14:50 – 15:10
break
15:10 – 16:10
2nd session
Please be on time to participate in sessions
Decision Making?
Decision making may be defined as:
Intentional and reflective choice in response to perceived needs (Kleindorfer
et al., 1993)
Decision maker’s (DM’s) choice of one alternative or a subset of alternatives
among all possible alternatives with respect to her/his goal or goals (Evren
and Ülengin, 1992)
Solving a problem by choosing, ranking, or classifying over the available
alternatives that are characterized by multiple criteria (Topcu, 1999)
Group Decision Making?
Group decision making is defined as a decision situation in which there are
more than one individual involved (Lu et al., 2007).
These group members have their own attitudes and motivations, recognise the
existence of a common problem, and attempt to reach a collective decision.
Moving from a single DM to a multiple DM setting introduces a great deal of
complexity into the analysis (Hwang and Lin, 1987).
­ The problem is no longer the selection of the most preferred alternative among the
nondominated solutions according to one individual's (single DM's) preference structure.
­ The analysis must be extended to account for the conflicts among different interest groups who
have different objectives, goals, criteria, and so on.
­ Synonyms: Collaborative decision making, multiple expert decision making, etc.
Group decision making under multiple criteria
It includes such diverse and interconnected fields as
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preference analysis, utility theory, social choice theory,
committee decision theory, theory of voting, game theory,
expert evaluation analysis, aggregation of qualitative factors,
economic equilibrium theory. etc;
«More than one DM» extension to
classical decision making problems
Problems defined by «More
than one DM» involvement
Group Decision Making
Group Decision
Making
Process Oriented
Approaches
Content Oriented
Approaches
Ö
Ö
Implicit
Multiattribute
Evaluation
Ö
Explicit
Multiattribute
Evaluation
Ö
Game-Theoretic
Approach
X
Process-oriented approaches
Some problems are highly complex, often interdisciplinary or transdisciplinary
with social, economic, political, and emotional factors intertwined with more
quantifiable factors of physical technology.
In such kind of pluralistic (interest of multiple stakeholders) situations the basic
objective is to understand the problem, understand the views of the other
stakeholders instead of find a «solution» to the problem.
Process-oriented approaches
(Techniques for Teams)
Brain Storming
Brain Writing
Nominal Group Technique
Delphi Method
Group Decision Making
Content-oriented approaches
­ Focuses on the content of the problem, attempting to find an optimal or satisfactory solution
given certain social or group constraints, or objectives
­ Implicit Multiattribute Evaluation (Social Choice Theory)
­ Explicit Multiattribute Evaluation
­ Game-Theoretic Approach
­ GT - the study of mathematical models of conflict and cooperation between intelligent rational decision-makers. «Interactive
decision theory»
Process-oriented approaches
­ Focuses on the process of making a group decision. The main objective is to generate new
ideas.
Content-Oriented Approaches
These techniques operate under the following
assumptions:
­ All participants of the group problem solving share the same set of
alternatives, but not necessarily the same set of evaluation criteria
­ Prior to the group decision-making process, each decision maker or group
member must have performed his own assessment of preferences.
­ The output of such analysis is a vector of normalized and cardinal ranking,
a vector of ordinal ranking, or a vector of outranking relations performed
on the alternatives.
Content-Oriented Approaches
Implicit Multiattribute Evaluation
­ (Social Choice Theory)
Explicit Multiattribute Evaluation
­ (Multiple Attribute Group Decision Making)
Game-Theoretic Approach
Social Choice
Arrow’s classical book (Kenneth J. Arrow. Individual Values and Social Choice.
John Wiley & Sons, New York, 2nd edition, 1963.)
"In a capitalist democracy there are essentially two methods by which social
choices can be made: voting, typically used to make "political" decisions, and
the market mechanism, typically used to make "economic" decisions.
In the emerging democracies with mixed economic systems, Great Britain,
France, and Scandinavia, the same two modes of making social choices
prevail, though more scope is given to the method of voting and decisions
based directly or indirectly on it and less to the rule of the price mechanism.
Elsewhere in the world, and even in smaller social units within the democracies,
social decisions are sometimes made by single individuals or small groups and
sometimes (more and more rarely in this modern world) by a widely
encompassing set of traditional rules for making the social choice in any given
situation, e.g., a religious code."
Social Choice Functions
Social choice functions are based on preferential voting system for social
choice
They can be viewed as aggregation procedures
A social choice function is a mapping which assigns a noneempty subset of the
potential feasible subset to each ordered pair consisting of a potential
feasible subset of alternatives and a schedule or profile of voters'
preferences
Explicit Multiattribute Evaluation
Explicit Evaluation: Multi Attribute Decision Making (MADM)
Multi-criteria decision making (MCDM) refers to making decision in the
presence of multiple and conflicting criteria.
All the MCDM problems share the following common characteristics:
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Multiple criteria: each problem has multiple criteria, which can be objectives or attributes.
Conflicting among criteria: multiple criteria conflict with each other.
Incommensurable unit: criteria may have different units of measurement.
Design/selection: solutions to an MCDM problem are either to design the best alternative(s) or
to select the best one among previously specified finite alternatives.
Explicit Multiattribute Evaluation
There are two types of criteria: objectives and attributes.
The MCDM problems can be broadly classified into two categories:
­ Multi-objective decision making (MODM) – continuos decision space
­ Multi-attribute decision making (MADM) – discrete decision space
Formally, MADM is making preference decisions such as selecting, ranking,
screening, prioritization, and classification over the available finite number of
alternatives that are characterized by multiple attributes that are usually
conflicting, weighted, and incommensurable
Explicit Multiattribute Evaluation
Classical MADM methods:
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1) Non-compensatory methods,
2) Scoring methods (Value based Methods),
3) Pairwise comparison methods (Analytic hierarchical process (AHP) methods)
4) Outranking methods
5) Linguistic approaches.
­ We will discuss group DM extentions of some of these methods.
Explicit Multiattribute Evaluation
New Trends: group decision making methods proposed in the high cited
papers will be analyzed.
Fuzzy set theory based methods
Cumulative Belief Degree Approach
Linguistic Evaluation & Consensus Measures
Contemporary GDM methods
Next week
Homework 1:
Please read the following paper and submit a one-page summary.
­ Kangas, Annika, Sanna Laukkanen, and Jyrki Kangas. (2006) Social choice theory and its
applications in sustainable forest management—a review. Forest Policy and economics 9.1, 7792.
Visit the webpage and dowload course material prior to the class.
Topic:
­ Content oriented methods
­ Preferential voting systems
­ Social Choice functions