DSS DESIGN I

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DSS DESIGN I

• IS4185 Session 8
• Prof. Mark Nissen

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Agenda

• DSS Design Goals Difficulties
• DSS Levels Strategies
• DSS Elements
• ROMC Approach Example

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DSS Design Goals

• Support human cognitive tasks involving
  decisions, judgment choice
• Differ from other IS?
• Search engine? Enrollment processing?
• Improve DM efficacy (efficiency?)
• Help structure decision making
• Easy to use, maintain conform to org processes
  DM styles
• Accurate, reliable trustworthy system
• Bridge gap between DM DSS builder

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DSS Levels Users

• DM often not IT specialist
• Specific DSS - knowledge worker
• Single application (restaurant advisor)
• DSS generator - modeler/builder
• Family of apps (heuristic source selection)
• RAD tools (LDW, DATA, InDia, VPExpert)
• DSS tools - IT specialist
• Basic tools (VBasic, C, Java, Oracle)
• Few people excel at all three

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Developmental Strategies
Formal DM Staff
End User Development
Development Development
Rigid rqmts Prototyping
Prototyping IS specialists
DM staff
User/DM IT Control Domain
understanding DM direct IT Quality
DM confidence Documentation
DM control High Expertise
Faster development Spec problem
IT
Control Expensive
IT
Quality Time-consuming
Doc
Strong
Weak
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DSS Design Difficulties

• Semi(un)structured problem solving
• DM generally not IT specialist
• Requirements hard to specify ex ante
• DM integral part of DSS, wide variation
• DSS evolution thru time
• Human judgment often hard to explain
• DSS may complicate impede DM
• Much group DM

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Informational Characteristics

• Task influences info requirements
• Inherent accuracy
• Required level of detail
• Time horizon
• Frequency of use
• Internal vs. external source
• Strategic vs. op scope
• Quantifiability
• Currency
• Also vary with decision maker?

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Behavioral Characteristics

• Holistic human DM vs. rationality
• Many (38), diverse DM strategies
• Cognitive limitations DM biases
• Human DM performance degrades - time pressure,
  stress, parallel rqmts
• Problems with aleatory information
• Contingency task structure (S1 F1.7)

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Contingency Task Structure

• DM environment
• Internal context
• External factors
• Decision maker?
• Task requirements
• DM/processing steps
• DM stress cost
• DM experiential familiarity with above
• Specific to DM, changes thru time

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DSS Elements
Decision Maker
DGMS
DBMS MBMS
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DSS Design Approach Decision-Maker Centric

• Analyze existing process (not BPR)
• Formalize decision problem
• Decision steps, variables models
• Preliminary KA/CSF analysis
• DM behavioral description
• ROMC T method
• Knowledge/data acquisition
• Rapid, iterative prototyping

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ROMC T Method

• DM requirements analysis
• Need process independent approach
• Support DMer idiosyncrasies, contextual
  variations available technologies
• Integrate with all formal decision phases
• Elements on DSS design palette
• Representations? Operations?
• Memory Aids? Controls?
• Technologies?
• ROMC is technology-neutral

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Representations

• How DM views interprets problem
• Can think of user screen displays
• Examples maps, tables, scatterplots charts,
  reports lists, models, rules, natural language
• Key how does DM represent problem without DSS?

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Operations

• Manipulations to data representations
• Help understand, analyze, interpret, etc
• Can think of user actions/analyses
• Examples
• create, retrieve, update, delete info
• plot, scale, mark, color, compare maps/graphs
• generate, edit, check reports/lists
• build, validate, execute, maintain models
• initiate, recall, verify, forward conversations
• develop, validate, search rules
• What does DM do w/o DSS?

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Memory Aids

• Assist short- long-term memory
• Can think of data sources
• Examples scratch space, memory, storage,
  reports, scripts, protocols, notes
• Key what aids does DM use without DSS?

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Controls

• How user interfaces with and uses DSS
• Can think of navigation mechanisms
• Examples input forms, menus, question-answer
  pairs, direct manipulation objects, commands,
  scripts, agents, others
• Key match flow of DM activity without DSS

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Technologies

• Technical artifacts that enable ROMC elements to
  be supported via computer
• Can think of IT tools
• Examples imaging, databases, languages, solvers,
  memory, magnetic storage, printers, networks,
  recorders, ES shells, ANNs, GAs, others
• Key what technologies are available, familiar
  low-risk?

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ROMC T Table
Letters (a-z) denote Rs, Os, Ms, Cs Ts
available on DSS designer palette
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Parking Example

• Student volunteer (drove today)
• Select parking space?
• Understand current process
• Design for improvement via DSS
• Intelligence - need for decision?
• ROMC T
• Design - generate alternatives?
• ROMC T
• Choice - select alternative?
• ROMC T