Types of Information System –
Decision Support Systems (DSS), and
Expert Systems
07th November 2011
Decision-Support Systems (DSS)
• A type of information system that provide
middle management with sophisticated data
and information analysis to support semistructured and unstructured decision making.
• Support non-routine decision making for
middle management
• Focus mainly on problems that are new and
unique – What is important here??
DSS
DSS use both internal and external information
• Internal: from information systems within the
organisation such as TPS and MIS
• External: from sources outside the
organisation such as current stock prices, new
legislation, etc
DSS
• DSS use a variety of models to effectively
analyse the data.
• Also use a range of techniques allowing for
condensing large amounts of data and
information into more effective formats.
– Some layouts are more effective than others!
– E.G. A graph may be more effective than a chart in
a given scenario
DSS
• DSS may vary in terms of how much they rely
on analytical models.
• For instance…
– one DSS may extensively use analytical models to
make complex decisions
– whereas another DSS may extensively extract
useful information from a large data source
instead
– Combinations of the above are often employed!
Voyage-Estimating DSS
This DSS operates on a powerful PC. It is used daily by managers who must develop
bids on shipping contracts.
Figure 2-5 (Laudon & Laudon)
DSS
• Example Case Study from Laudon & Laudon
• P. 489 Renault DSS
Expert System
• A type of information system that captures
the expertise of a human in limited domains
of knowledge (Laudon & Laudon)
• These systems capture the knowledge of
skilled employees in the form of explicit rules
so as to enable others in the organisation to
avail of them!
Expert System
• These explicit rules captured by the expert
system contributes to the stored learning of
the firm.
• Expert systems lack the information
processing capabilities of humans! Therefore
expert systems are limited in their field of
application!
Expert System – How they work
• They model human knowledge in a way that
the computer will be able to process it.
– This knowledge is modelled as a set of rules –
collectively known as the knowledge base
• Typically model from between hundreds to
thousands of explicit rules depending on the
complexity of the problem
Expert System – How they work
• Strategy used to search through the
knowledge base is called the inference engine.
• The inference engine relies mainly on one of 2
strategies:
1. Forward Chaining
2. Backward Chaining
Office Automation Systems
• A type of information system that supports a
range of office activities that lead to improved
work flow between workers.
• Office automation systems often enable more
effective and efficient processing of office
activities such as calculating paychecks,
sending automated emails, providing instant
access for a credit card processor to validate
credit cards, etc