IENG 423 Design of Decision Support Systems Decision Support System Concepts.
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Transcript of 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
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 systemMost 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
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
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 Access, MySQL, Oracle, …
Decision Support Systems
Requires a high level of expertise Complex chains of decisions Work through set of logical inferences 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 Expert systems, VP-Expert, custom application
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 systemis intended to compliment the human useris not intended to replace expertise and human judgmentis 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 makingHave been around for a while, buttake advantage of modern technologyA variety of modern information system tools make powerful Decision Supports Systems widely available and accessible