Imprecision of specification of information systems parameters: A study of decision point probabilities

摘要

In the development of computer aided information systems one observers a lack of sufficient data for doing systems design and for predicting information systems performance. This creates a need for soliciting additional information from the user community. Assuming that quantification is made more convenient for the users if they are allowed to specify the system using terms in their natural language, the emphasis of this article is to show how to include such terms in the systems quantitative description.The conventional mathematical theory that shows how to solve simple and precise linear equations is extended to linguistic or imprecise equations arised from linguistic statements about system parameters. Only one parameter type, transition probabilities, is investigated here. It is argued that this parameter type plays an essential part in information system analysis. The statements can be of two types, absolute or relative. When stated in absolute terms the parameters refer directly to a common base variable. When stated in relative terms they are stated in terms of each other. Specification in linguistic terms supplements classical numeric specification.Specification inconsistencies are also discussed.