Precise Enterprises and Imperfect Data

One of the main uses of an information system is the representation and management of large amounts of indicative information from multiple sources describing the state of some enterprise. Most current information systems model enterprises that are crisp. A crisp enterprise is defined as one that is highly quantifiable; all relationships are fixed, and all attributes are atomic valued. The premises on which this paper is based are precise enterprises, where data are imperfect. In such cases information can be certain, imprecise or uncertain, temporal, or any possible combination of each two of them, depending on the application domain. Additionally, in domains where the information is perfect, all information sources are absolutely reliable and trustworthy. In more speculative domains, like diagnosis, where, information may be asserted relatively to some time intervals in which it is possibly defined and probably believed. In such domains different sources of information may be assigned different degrees of reliability. This paper is presenting a framework for the conceptual integration and uniform treatment of all these types of