Computer-Based Applications: Decision Support Systems Version 4.0 - 10/18/99Note to the Student:Quick ReviewsSimon’s Model Flowchart of Decision ProcessIntelligence PhaseDesign PhaseChoice PhaseThe role of models in decision-makingPounds’ Categories of Models - Expectations against which reality is measuredAnother classification of modelsIconic and Analog ModelsMathematical ModelsMental ModelsDecision (Cognitive) StylesThe Origins of DSS:Origins of DSS: Problems with OR/MSOrigins of DSS: Problems with MISOrigins of DSS: Early WorkCharacteristics of Ill-Structured ProblemsCharacteristics of Ill-Structured Problems - 2Decision Support System Origins: Just Another BuzzwordContradictory Claims and Observations about DSSOrigins of DSS: The first DSSScott-Morton: Management Decision SystemsKeen and Scott Morton: DSSKeen and Scott-Morton: Three Purposes of a DSSDSS: Current DefinitionsDSS: Current Definitions - 2The Role of MISThe Role of OR/MSThe Role of DSS in the context of MIS and OR/MSDSS: Working DefinitionExamples of Problem solving with DSSIdealized Characteristics and Capabilities of a DSSIdealized Characteristics and Capabilities of a DSS - 2Idealized Characteristics and Capabilities of a DSS - 3Sensitivity AnalysisWhat-If AnalysisGoal SeekingDSS ComponentsDSS: Early ResearchModel ManagementSlide 43Model Base ManagementTypes of Models: StrategicTypes of Models: TacticalTypes of Models: OperationalModel Building BlocksCommunication Dialogue SubsystemNew DirectionsNew Directions - 2New Directions - 3Organizational Issues in DSS DevelopmentGroup Decision Support SystemsCharacteristics of GDSSCharacteristics of GDSS - contd.CIS 465 - Decision Support Systems - Fall 1999 1Computer-Based Applications:Decision Support SystemsVersion 4.0 - 10/18/99CIS 465 - Decision Support Systems - Fall 1999 2Note to the Student:•Previous lectures have dealt with the theoretical background of decision-making - both at the individual and group levels.•This lecture begins to look at the actual building of application systems for decision support: so-called decision support systems.•Decision Support Systems are abbreviated as DSS.CIS 465 - Decision Support Systems - Fall 1999 3Quick Reviews•Simon’s Model of Decision Making•ModelsCIS 465 - Decision Support Systems - Fall 1999 4Simon’s ModelFlowchart of Decision ProcessIntelligenceDesignChoiceCIS 465 - Decision Support Systems - Fall 1999 5Intelligence Phase•Organizational Objectives•Search and SCANNING Procedures•Data Collection•Problem Identification•Problem Classification•Problem StatementCIS 465 - Decision Support Systems - Fall 1999 6Design Phase•Formulate a Model•Set Criteria for Choice•Search for Alternatives•Predict and Measure OutcomesCIS 465 - Decision Support Systems - Fall 1999 7Choice Phase•Solution to the Model•Sensitivity Analysis•Selection of best (good) alternative(s)•Plan for implementation (action)•Design of a control systemCIS 465 - Decision Support Systems - Fall 1999 8The role of models in decision-making•A major characteristic of decision-making is the use of models.•A model is a simplified representation or abstraction of reality.•It is usually simplified because reality is too complex to copy.•Basis idea is that analysis is performed on a model rather than on reality itself.CIS 465 - Decision Support Systems - Fall 1999 9Pounds’ Categories of Models - Expectations against which reality is measured•Historical - expectation based on extrapolation of past experience.•Planning - the plan is the expectation•Inter-organizational - Models of other people in the organization (e.g. superiors, subordinates, other departments, etc.)•Extra-organizational - models where the expectations are derived from competition, customers, professional organizations, etc.CIS 465 - Decision Support Systems - Fall 1999 10Another classification of models•Iconic Models•Analog Models•Mathematical Models•Mental ModelsCIS 465 - Decision Support Systems - Fall 1999 11Iconic and Analog Models•Iconic (scale) models - the least abstract model, is a physical replica of a system, usually based on a different scale from the original. Iconic models can scale in two or three dimensions.•Analog Models - Does not look like the real system, but behaves like it. Usually two-dimensional charts or diagrams. Examples: organizational charts depict structure, authority, and responsibility relationships; maps where different colors represent water or mountains; stock market charts; blueprints of a machine; speedometer; thermometerCIS 465 - Decision Support Systems - Fall 1999 12Mathematical Models•Mathematical (quantitative) models - the complexity of relationships sometimes can not be represented iconically or analogically, or such representations may be cumbersome or time consuming.A more abstract model is built with mathematics. • Note: recent advances in computer graphics use iconic and analog models to complement mathematical modeling.• Visual simulation combines the three types of models.CIS 465 - Decision Support Systems - Fall 1999 13Mental Models•People often use a behavioral mental model.•A mental model is an unworded description of how people think about a situation.•The model can use the beliefs, assumptions, relationships, and flows of work as perceived by an individual. •Mental models are a conceptual, internal representation, used to generate descriptions of problem structure, and make future predications of future related variables.•Support for mental models are an important aspect of Executive Information Systems. We will discuss this in depth later.CIS 465 - Decision Support Systems - Fall 1999 14Decision (Cognitive) Styles•Analytic - planned, sequential approach; learn by analyzing; less emphasis on feedback; formal•Heuristic - learn more by acting than analyzing situations; extensive feedback; intuition, common sense; trial and error.•Autocratic vs. democraticCIS 465 - Decision Support Systems - Fall 1999 15The Origins of DSS:•The DSS movement grew out of dissatisfaction with two earlier and very successful applications of technology to management:–Operations Research and Management Science (OR/MS)–Management Information Systems (MIS)•By 1970 both technologies were viewed as too limited to:–meet growing demand of managers for more effective decision support–make proper use of the expanding capabilities of information processing technologyCIS 465 -