Decision Support Systems Oracle Tips by Burleson Consulting

High Performance Data Warehousing

Decision Support Systems And Expert Systems 

Decision Support Systems And Data Warehouses

Decision support systems (DSS) are generally defined as the class of warehouse system that deals with solving a semi-structured problem. In other words, the task has a structured component as well as an unstructured component. In short, the unstructured component involves human intuition and requires human interaction with the DSS. The well-structured components of a DSS are the decision rules stored as the problem-processing system. The intuitive, or creative, component is left to the user.

The following represent some examples of semi-structured problems:

* Choosing a spouse. While there are many structured rules (I want someone of my religion, who is shorter than me), there is still the unstructured, unquantifiable component to the process of choosing a spouse.

* Choosing a site for a factory. This is a nonrecurring problem that has some structured components (cost of land, availability of workers, and so on), but there are many other unstructured components in this decision (i.e., quality of life).

* Choosing a stock portfolio. Here the structured rules are the amount of risk and the performance of stocks, but the choice of stocks for a portfolio requires human intuition.
Decision support technology recognizes that many tasks require human intuition. For example, the process of choosing a stock portfolio is a task which has both structured and intuitive components. Certainly, rules are associated with choosing a stock portfolio, such as diversification of the stocks and choosing an acceptable level of risk. These factors can be easily quantified and stored in a database system, allowing the user of the system to create what-if scenarios. However, just because a system has well-structured components does not guarantee that the entire decision process is well-structured.

One of the best ways to tell if a decision process is semi-structured is to ask the question, Do people with the same level of knowledge demonstrate different levels of skill? For example, it’s possible for many stock brokers to have the same level of knowledge about the stock market. However, these brokers will clearly demonstrate different levels of skill when assembling stock portfolios.

Computer simulation is one area used heavily within the modeling components of decision support systems. In fact, one of the first object-oriented languages was SIMULA. SIMULA was used as a driver for these what-if scenarios and was incorporated into decision support systems so that users could model a particular situation. The user would create a scenario with objects subjected to a set of predefined behaviors.

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This is an excerpt from "High Performance Data Warehousing", copyright 1997.

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