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IENG 423 Design of Decision Support Systems. Decision Support System Concepts. Decision Support Systems . Recall the house selling problem- Offer A: $180,000 Offer B: $150,000 Goal: maximize the amount received for the house. Decision Support Systems .
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IENG 423Design of Decision Support Systems Decision Support System Concepts
Decision Support Systems • Recall the house selling problem- • Offer A: $180,000 • Offer B: $150,000 • Goal: maximize the amount received for the house
Decision Support Systems • So, what is the problem in making this decision? • Decision: accepting offer A satisfies the goal, so offer A it is. • Do we need a support system to make this decision? • Probably not.
Decision Support Systems • So, when do we need a decision support system • Most real-world decision making faced by company, government and other decision makers is more complex than this
Decision Support Systems • We have already talked about some complications… • Multiple objectives • Conflicting objectives • Subjective Expected Utility of decision makers
Decision Support Systems • But there are other complications to decision making • Requires new knowledge or skill • We are missing piece of knowledge or skill needed to figure it out • Computational demand too high • We could calculate a solution but is it too complex for decisions in reasonable time • Data acquisition load too high • There’s too much data to retrieve or analyze to make the appropriate decision • Requires a high level of expertise
Decision Support Systems Requires new knowledge or skill • We don’t know how to figure it out • Back to selling our house • Offer A: $180,000 • Offer B: ¥15,000,000 • Which do you choose? • Missing knowledge • How do we fix this problem? • www.xe.com
Decision Support Systems Requires new knowledge or skill • We don’t know how to figure it out • …but how? • One off – research project – analyst • Individual self study • Group learning process – skill development • Training • The Internet (Google)
Decision Support Systems Requires new knowledge or skill • We don’t know how to figure it out • We need to gain a skill or some new knowledge to figure it out • Can you tie a Winsor knot or a bowline? • Should I prune the grape vines in my vineyard? • You are in charge of a baby bottle factory. • Bisphenol A makes plastic more heat resistant • Should you use it as in ingredient in the baby bottles
Decision Support Systems • Computational demand too high • We could calculate a solution but is it too complex for decisions in reasonable time • You work for a school board and you have been asked to figure out the financial and performance implications of replacing a fleet of school buses to hybrids (hydrocarbon fuel/battery) • Under difference scenarios – all or phased, several different vendors, gasoline, ethanol, ethanol from lunch room wastes, E85,…) • Could you calculate this? Yes • Would it be easy? No • Computational modeling – simulations, forecasts, spreadsheets • Excel
Decision Support Systems • Computational demand too high • Model Based DSS • Tools • Excel • Packaged modeling tools • Corporate models • Custom software
Decision Support Systems • Data acquisition load too high • There’s too much data to retrieve and/or analyze to make the appropriate decision • You work for a clothing manufacturer that regularly bids on contracts to provide uniforms in large quantities • Your colleagues have to select from hundreds of textile suppliers, each with 100s of fabrics with a variety of qualities and characteristics, different levels of availability, and at various prices…
Decision Support Systems • Data acquisition load too high • There’s too much data to retrieve and/or analyze to make the appropriate decision • Clothing bids …continued… • How do you find the right materials to bid this job and satisfy the resulting contract • Start calling the suppliers • Thumb through catalogs • Retrieve the needed data from a database
Decision Support Systems • Data acquisition load too high • Data-driven DSS • Tools • RDBS – Oracle, MySQL, MS-Access
Decision Support Systems • Requires a high level of expertise • Complex chains of decisions • Work through set of logical inferences and deductions • Triage in a hospital emergency room • Patient: Male, 65 years old, escaped from structure fire in home, minor burns on arms and legs, chest pains, shortness of breath,… • Decision: what to do- apply treatment, get more data (blood test) • Replicate the behavior of a human expert • Provide expert consultation to a human decision maker • Expert systems, VP-Expert, custom application
Decision Support Systems • Requires a high level of expertise • Expert System driven DSS • Tools- • Expert systems, VP-Expert, custom application
Decision Support Systems • Group DSS • Support group decision making processes • Sometimes referred to as Communications driven DSS • “facilitate the solution to problems by decision makers working together as a group” • Sometimes – Groupware • Chat, email, bulletin boards • Wikis • Collaboration tools
Decision Support Systems • Web-based DSS • An interesting distinction in terms of a DSS • Why? • What are the important features of a Web-based DSS?
What is a Decision Support System? • “Any information system that is not a transaction processing system” • …so what is a transaction processing system? • …not a good definition!
What is a Decision Support System • …not the same as a Management Information System (MIS) • …not the same as a data processing system
What is a Decision Support System • Decision Support Systems… • “Assist managers in their decision making processes in semistructured tasks.” • “Support, rather than replace, managerial judgment.” • “Improve the effectiveness of decision making rather than efficiency” • from: Peter Keen and Michael Morton, “Decision Support Systems: An Organizational Perspective” Addison Wesley, 1978
What is a Decision Support System? • “Decision support systems are a class of computer-based information systems including knowledge based systems that support decision making activities. “ • from Wikipedia • http://en.wikipedia.org/wiki/Decision_support_system
What is a Decision Support System • For our purposes- • an Information System • computer based • support decision making • that means there are decisions to make • decisions are information based • designed for specific target users • designed for critical decisions • designed for recurrent use (usually)
What is a Decision Support System? • A DSS must – • Address a problem area or domain • Have a set of target users (decision makers) • Have a set of goals – one or more • Have a set of decisions that address each of the goals • Each decision must be supported by information (data elements, reports, projections, etc.) • Each decision must have a set of alternatives (choices) • Each alternative must have an associated action
What is a Decision Support System? • A DSS should have • Metrics – measures of performance in terms of system goals • Feedback – a way to assess the effectives of the DSS in supporting the decision making process
What is a Decision Support System? • A DSS must – • have a means to collect and store relevant data • have a means to retrieve, filter and organize relevant data • have a mechanism to process, transform, and analyze information • have the ability to deliver or present information in decision relevant ways (interface)
A Decision Support System • is not a completely automated system • is intended to compliment the human user • is not intended to replace expertise and human judgment • is intended to make decision making better or even possible in situation where it would be difficult or impossible
Decision Support Systems • Can use a range of tools to support decision making • Have been around for a while, but • take advantage of modern technology • A variety of modern information system tools make powerful Decision Supports Systems widely available and accessible
Decision Support Systems • Applications Where do you find DSSs • Manufacturing • Agriculture • Homeland Security • Urban Planning • Medicine • and anything else