Representing Knowledge About Information Systems in Telos

Abstract

Telos is a language intended to support the development of information systems. The design principles for the language are based on the premise that information system development is knowledge-intensive and that the primary responsibility of any language intended for the task is to be able to formally represent the relevant knowledge. Telos’ features include: an object-centered framework which supports aggregation, generalization and classification; a novel treatment of attributes; an explicit representation of time; and facilities for specifying integrity constraints and deductive rules. The language is appropriate for representing knowledge about a variety of worlds related to an information system, such as the subject world (application domain), usage world (user models, environments), system world (software requirements, design), and development world (teams, methodologies).

We gratefully acknowledge the contrjbution of insightful ideas, suggestions and moral support from Sol Greenspan (GTE Laboratories, Waltham, MA) whose thesis provided a rationale and a springboard for this research; Yannis Vassiliou, Thodoros Topaloglou, Manolis Marakakis and others (Institute of Computer Science, Iraklion, Crete, Greece) for serving as first users of the language; John Gallagher and Levy Solomon (SCS Technische Automation and Systeme GmbH, Hamburg, Germany), who did the first implementation of CML; Thomas Rose, Manfred Jeusfeld and others (University of Passau, Germany) who carried out an implementation of Telos; as well as other members of the ESPRIT projects LOKI and DAIDA. Last, but not least, we would like to thank Lawrence Chung, Brian Nixon, Martin Stanley and other members of the Taxis group at the University of Toronto for providing a friendly and stimulating research environment.