Turbanchap03.ppt

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CHAPTER 3
Decision Support Systems:
An Overview

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Decision Support Systems
 Decision Support Methodology
 Technology Components
 Development
Decision Support Systems and Intelligent Systems, Efraim Turban and Jay E. Aronson, 6th edition
Copyright 2001, Prentice Hall, Upper Saddle River, NJ

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Decision Support Systems:
An Overview
 Capabilities
 Structure
 Classifications
Decision Support Systems and Intelligent Systems, Efraim Turban and Jay E. Aronson

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DSS Configurations
 Supports individuals and teams
 Used repeatedly and constantly
 Two major components: data and models
 Web-based
 Uses subjective, personal, and objective data
 Has a simulation model
 Used in public and private sectors
 Has what-if capabilities
 Uses quantitative and qualitative models

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DSS Definitions
 Little (1970)
“model-based set of procedures for processing
data and judgments to assist a manager in his
decision making”
Assumption: that the system is computer-based
and extends the user’s capabilities.
 Alter (1980)
Contrasts DSS with traditional EDP systems
(Table 3.1)

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TABLE 3.1 DSS versus EDP.
Dimension DSS EDP
Use Active Passive
User Line and staff
management
Clerical
Goal Effectiveness Mechanical
efficiency
Time
Horizon
Present and future Past
Objective Flexibility Consistency
Source: Alter [1980].

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 Moore and Chang (1980)
1. Extendible systems
2. Capable of supporting ad hoc data analysis and
decision modeling
3. Oriented toward future planning
4. Used at irregular, unplanned intervals
 Bonczek et al. (1980)
A computer-based system consisting of
1. A language system -- communication between the user
and DSS components
2. A knowledge system
3. A problem-processing system--the link between the
other two components

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 Keen (1980)
DSS apply “to situations where a ‘final’ system can
be developed only through an adaptive process of
learning and evolution”
 Central Issue in DSS
support and improvement of decision making

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TABLE 3.2 Concepts Underlying DSS Definitions.
Source DSS Defined in Terms of
Gorry and Scott Morton [1971] Problem type, system function (support)
Little [1970] System function, interface
characteristics
Alter [1980] Usage pattern, system objectives
Moore and Chang [1980] Usage pattern, system capabilities
Bonczek, et al. [1996] System components
Keen [1980] Development process

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Working Definition of DSS
 A DSS is an interactive, flexible, and adaptable CBIS,
specially developed for supporting the solution of a
non-structured management problem for improved
decision making. It utilizes data, it provides easy user
interface, and it allows for the decision maker’s own
insights
 DSS may utilize models, is built by an interactive
process (frequently by end-users), supports all the
phases of the decision making, and may include a
knowledge component

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Characteristics and Capabilities of
DSS(Figure 3.1)
1. Provide support in semi-structured and unstructured
situations, includes human judgment and
computerized information
2. Support for various managerial levels
3. Support to individuals and groups
4. Support to interdependent and/or sequential decisions
5. Support all phases of the decision-making process
6. Support a variety of decision-making processes and
styles
(more)

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7. Are adaptive
8. Have user friendly interfaces
9. Goal: improve effectiveness of decision making
10. The decision maker controls the decision-making
process
11. End-users can build simple systems
12. Utilizes models for analysis
13. Provides access to a variety of data sources,
formats, and types
Decision makers can make better, more consistent
decisions in a timely manner

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DSS Components
1. Data Management Subsystem
2. Model Management Subsystem
3. Knowledge-based (Management) Subsystem
4. User Interface Subsystem
5. The User
(Figure 3.2)

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DSS Components
User
User Interface
DBMS MBMS
KBS3
KBS2
KBS1

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The Data Management Subsystem
 DSS database
 Database management system
 Data directory
 Query facility
(Figure 3.3)

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DSS In Focus 3.2: The Capabilities of DBMS in a DSS
 Captures/extracts data for inclusion in a DSS database
 Updates (adds, deletes, edits, changes) data records and files
 Interrelates data from different sources
 Retrieves data from the database for queries and reports
 Provides comprehensive data security (protection from unauthorized access, recovery
capabilities, etc.)
 Handles personal and unofficial data so that users can experiment with alternative
solutions based on their own judgment
 Performs complex data manipulation tasks based on queries
 Tracks data use within the DSS
 Manages data through a data dictionary

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DSS Database Issues
 Data warehouse
 Data mining
 Special independent DSS databases
 Extraction of data from internal, external, and private
sources
 Web browser data access
 Web database servers
 Multimedia databases
 Special GSS databases (like Lotus Notes / Domino
Server)
 Online Analytical Processing (OLAP)
 Object-oriented databases
 Commercial database management systems (DBMS)

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The Model Management
Subsystem
 Analog of the database management subsystem
(Figure 3.4)
 Model base
 Model base management system
 Modeling language
 Model directory
 Model execution, integration, and command
processor

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Model Management Issues
 Model level: Strategic, managerial (tactical), and
operational
 Modeling languages
 Lack of standard MBMS activities. WHY?
 Use of AI and fuzzy logic in MBMS

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The Knowledge Based
(Management) Subsystem
 Provides expertise in solving complex
unstructured and semi-structured problems
 Expertise provided by an expert system or other
intelligent system
 Advanced DSS have a knowledge based
(management) component
 Leads to intelligent DSS
 Example: Data mining

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The User Interface (Dialog)
Subsystem
 Includes all communication between a user and
the MSS
 Graphical user interfaces (GUI)
 Voice recognition and speech synthesis possible
 To most users, the user interface is the system

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The User
Different usage patterns for the user, the
manager, or the decision maker
 Managers
 Staff specialists
 Intermediaries
1. Staff assistant
2. Expert tool user
3. Business (system) analyst
4. GSS Facilitator

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DSS Hardware
Evolved with computer hardware and
software technologies
Major Hardware Options
 Mainframe
 Workstation
 Personal computer
 Web server system
– Internet
– Intranets
– Extranets

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Distinguishing DSS from
Management Science and MIS
 DSS is a problem-solving tool and is
frequently used to address ad hoc and
unexpected problems
 Different than MIS
 DSS evolve as they develop

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DSS Classifications
Alter’s Output Classification (1980)
 Degree of action implication of system outputs
(supporting decision) (Table 3.3)
 Holsapple and Whinston’s Classification
1. Text-oriented DSS
2. Database-oriented DSS
3. Spreadsheet-oriented DSS
4. Solver-oriented DSS
5. Rule-oriented DSS
6. Compound DSS

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Intelligent DSS Categories
 Descriptive
 Procedural
 Reasoning
 Linguistic
 Presentation
 Assimilative

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Alternate Categories of
Intelligent DSS
 Symbiotic
 Expert-system based
 Adaptive
 Holistic

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Other Classifications
Institutional DSS vs. Ad Hoc DSS
 Institutional DSS deals with decisions of a recurring
nature
 Ad Hoc DSS deals with specific problems that are
usually neither anticipated nor recurring

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Other Classifications (cont’d.)
 Degree of nonprocedurality (Bonczek et al., 1980)
 Personal, group, and organizational support
(Hackathorn and Keen, 1981)
 Individual versus group support systems (GSS)
 Custom-made versus ready-made systems

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Summary
 Fundamentals of DSS
 Components of DSS
 Major capabilities of the DSS components
 Major DSS categories

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