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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)?.
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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 decision-making 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 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 knowledge. • Extend the decision makers ability to tackle large-scale, time-consuming 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. • The DataBase(Knowledge base). • The Model (the decision context and user criteria). • 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 • Data Manipulation • Data Integrity • Access control • Concurrency Control • Transaction Recovery
DSS Model base Management System (MBMS) • 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 • General function of MBMS • Modelling language • Model library • Model manipulation
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 • Knowledge Acquisition: The process when the knowledge engineer acquire (interview) the domain experts in order to gather the facts and their relationships and store it in the knowledge base • Knowledge retrieval: The process where the interface engine retrieve facts or rules from the knowledge base in an organised manner in order to assess decisions or conclusions
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 • 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 • Communication Language: • It deals with activities related to users direct dialog with DSS including the various data entry modes. • It allows the user to transmit information and comments to the DSS • General Functions of DSS Interface • 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
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