Decision Support System
Week 1
Reference (chapter 1 in text book (1))
Dr. Fadi Fayez Jaber
Updated By: Ola A.Younis
What is Decision Support System
(DSS)?
 A computer-based information system that
supports business or organizational decisionmaking activities. DSSs serve the management,
operations, and planning levels of an organization
(usually mid and higher management) and help to
make decisions, which may be rapidly changing
and not easily specified in advance. Decision
support systems can be either fully computerized,
human or a combination of both.
DSS Common Characteristics
 Employed in semi-structured or unstructured decision context.
 Intend to support decision makers rather than replace them.
 Focuses on the effectiveness of decision making process rather than the
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efficiency.
Support all phases of decision making process.
Uses underlying data and models.
Facilitates learning on the part of the decision making.
Interactive and user friendly.
Provide supports for all levels of management.
Provide support for individuals, groups.
History of DSS and its Potential Future
History
 The theoretical studies of organizational decision making done at the
Carnegie Institute of Technology during the late 1950s and early
1960s*.
 The technical work on Technology in the 1960s*.
 DSS became an area of research of its own in the middle of the 1970s,
before gaining in intensity during the 1980s*.
Future
 Managers will rely on powerful DSS applications in performing their
daily activities
 DSS will serve as the primary vehicle for keeping up with the
exponential growth, complexity and speed of business activities
* Wiki
DSS Benefits
 Extend the decision makers ability to process information and
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knowledge.
Extend the decision makers ability to tackle large-scale, timeconsuming and complex problems.
Shorten the time associated with making the decision.
Improve the reliability of a decision process or outcome.
Encourage exploration and discovery on the part of the decision
maker.
Reveal new approaches to thinking about the problem space or
decision context.
DSS Limitations
 DSSs cannot yet be designed to contain distinctly human decision-
making talents such as creativity.
 The power of DSS is limited by computer science upon which is
running.
 DSS interfaces are not yet sophisticated enough to allow for
natural language processing of users inquiries.
 DSSs are designed to be narrow in the scope of applications.
DSS Basic Components
 The Data Management System.
 Model Management System.
 Knowledge Engine.
 User Interface.
 Users.
Data Management System
 Database organises the data into logical hierarchy based on the degree of aggregation
of the data.
 The hierarchy consists of four elements
 Database
 Files
 Records
 Data Elements
 Database Management Systems (DBMS) manages and organises the access and
operations on the database
 DBMS has two primary responsibilities:
 Coordination of tasks related to storing and accessing information in the database and
delivering information to the DSS users
 The maintenance of logical independence between the data contained in the DSS database
and the DSS application
Main Functions of the DBMS
 Data Definition and extraction
 Data Manipulation
 Data Integrity
 Access control
 Concurrency Control
 Transaction Recovery
Model Management Sub-System (MMSS)
 A model: is a simplification of some event or process constructed for
the purpose of studying that event in order to better understand it
 Two primary responsibilities:
 Execution and integration of the models available to the DSS
 Modelling of users preferences
 MMSS is composed of:
 1- Model base
 2- Model base management system.
 3- Modelling language.
 4- Model directory.
 5- Model execution, integration and command processor.
DSS Knowledge Base
 All decisions require reasoning
 Reasoning : the process by which new information is derived from existing data or
information
 Knowledge base is where the “knowledge” of the DSS is stored
 Knowledge can be represented as simple if-then rules, heuristics, previous outcomes
or information that may have been programmed into the DSS by the designer
 Information in the knowledge base can be categorised into 2 groups:
 Facts: What we know is true at a given time
 Hypotheses: The rule or relationships that exist between facts.
Decision support system that includes KBS is called intelligent DSS.
DSS User Interfaces
 An interface: a component of a system intended to allow the user to access the
internal components of that system
 DSS interface is responsible for all communication and interaction with the user(s)
 DSS interface components
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Software components, i.e. menus and command interfaces
Hardware components, i.e. input facility and multiple monitoring
Factors related to Human Computer Interaction (HCI)
Accessibility, user skill level, reporting and error capture
 Some MSS experts feels that the user interface is the most important
component… why????
 General Functions of DSS Interface
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Allow the interaction with DSS in a variety of dialog styles
Identify the form of input to enter request to the DSS
Provide support for communication among multiple DSS users
Can capture and analyse previous dialogs so that future interactions can be improve
DSS User Interfaces (Cont.)
 The Presentation Language :
 it’s the place where all actions is. In other words, it is everything
where the user can sees, hears or experience during DSS use.
 Output devices such as printers, audio monitors, etc
 On-screen methods such as tables, graphs, charts, icons, ect, are all
part of this component modes.
 General Functions of the Presentation Language
 Provides for the presentation of data in different forms
 Allow for detailed report definition and generation
 Allow for the creation of multiple forms, tables, graphs, etc
 Can provide multiple windows or views of data
The User
Different usage patterns for the user, the
manager, or the decision maker
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Managers
Staff specialists
Intermediaries
1. Staff assistant
2. Expert tool user
3. Business (system) analyst
4. GSS Facilitator
DSS Hardware
Evolved with computer hardware and
software technologies
Major Hardware Options
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Mainframe
Workstation
Personal computer
Web server system
 Internet
 Intranets
 Extranets
Distinguishing DSS from
Management Science and MIS
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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
Categories and Classes of DSS
 Data-centric and model-centric DSSs
 Formal and Ad hoc systems
 Directed versus non-directed DSSs
 Procedural and non-procedural systems
 Hypertext systems
 Spread sheet systems
 Individual and group DSSs