Enforcing Business Rules by the Application of Trigger Concepts

Purpose	The concept of event-driven systems has gained much attention in recent years as well in computer science as in business administration. Central notions in this concept are triggers and business rules. One goal of this research project is to evaluate the potential of trigger mechanisms for business applications.
Keyresults	Development of a classification system for business rules. Evaluation of applicability of the most common analysis methods for specifying business rules. Three information systems were analyzed with respect to business rules. Comparison of the trigger mechanisms available in Ingres, Oracle and Sybase. The transformation of triggers implemented in application programs to the DBMS level was studied in a large case study. A rule repository was developed for representing business rules and for deriving specialized views (e.g. Entity-Relationship models, Petri nets) on the rules.
Methods	Theoretical study (classification) on the types of business rules. Empirical research on existing IS with respect to trigger mechanisms trigger functionalities of commercial DBMS the reengineering potential of DBMS trigger functionalities. Modeling of business rules on the basis of the event-condition-action-action (ECAA) paradigm. Development of a rule repository BURRO.
Validation	Test of the classification system by results of case studies Information for user community on trigger mechanisms available in leading DBMS products Reports on practical experiences with applying database triggers Demonstration of rule repository to cooperation partners.
Perspectives	The results obtained until the end of this project in 1994 are summarized in [KnHS94]. Several research issues were identified during the project; thus far two of them were further investigated. Conceptual Level Our modeling approach is based on a meta-model which encompasses business rules and related facts like processes, processors/actors, organizational units, and rule origins. To support conceptual modeling, a rule repository system has been designed and implemented as a prototype on top of the repository system Rochade. The rule repository supports the classification of business rules and allows to derive graphical representations of different views on business rules and other components of the meta-model. The rule oriented conceptual modeling and the repository system have been sucessfully used for the documentation of a large case study in cooperation with Schweizerische Mobiliar Versicherungsgesellschaft. Physical Level Active DBMS support the definition and processing of ECA rules. Several commercially available DBMS encompass different types of active mechanisms. Based on the recognized shortcomings of active DBMS-mechanisms available, we design and implement parts of an active layer to be set on top of an arbitrary DBMS. Business Rules and Workflow Management Another highly relevant research area is the application of business rules for conceptual specification of workflow systems. In cooperation with the DBTG of the University of Zurich we intend to combine the rule repository with the active DBMS SAMOS in the SWORDIES project. Selected Publications Herbst, H., A Meta-Model for Specifying Business Rules in Systems Analysis, in: J. Iivari, K. Lyytinen, M. Rossi (Eds.), Proceedings of the Seventh Conference on Advanced Information Systems Engineering (CAiSE '95), Berlin et al.: Springer 1995, pp. 186-199. Herbst, H., Business Rules in Systems Analysis: A Meta-Model and Repository System, to appear in: Information Systems 21 (1996). Herbst, H., Knolmayer, G., Ansätze zur Klassifikation von Geschäftsregeln, in: Wirtschaftsinformatik 37 (1995) 2, pp. 149-159. Herbst, H., Myrach, T., A Repository System for Business Rules, in: R. Meersman and L. Mark (Eds.), Proceedings of the Sixth IFIP TC-2 Working Conference on Data Semantics, London: Chapman & Hall 1996. Herbst, H., Knolmayer, G., Myrach, T., Schlesinger, M., The Specification of Business Rules: A Comparision of Selected Methodologies, in: A.A. Verrijn-Stuart, T. W. Olle (Eds.), Methods and Associated Tools for the Information System Life Cycle, Amsterdam et al.: Elsevier 1994, pp. 29-46. Knolmayer, G., Herbst, H., Business Rules, in: Wirtschaftsinformatik 35 (1993) 4, pp. 386-390. Knolmayer, G., Herbst, H., Schlesinger, M., Enforcing Business Rules by the Application of Trigger Concepts, in: Swiss National Science Foundation (Ed.), Proceedings Priority Programme Informatics Research, Information Conference Module 1, Bern: Swiss National Science Foundation 1994, pp. 24-30 [KnHS94]. Knolmayer, G., Schlesinger, M., Geschäftsregeln in einem System der Liegenschaftsverwaltung und ihre Abbildbarkeit in einem kommerziell verf gbaren Datenbanksystem, in: GI-Datenbank-Rundbrief (1994) 14, pp. 28-31. 1 Knolmayer, G., Schlesinger, M., SQLForms-Trigger in Oracle-Datenbank-Trigger transformieren, in: Datenbank FOKUS (1995) 4, pp. 56-60. Schlesinger, M., Vergleich der Triggermechanismen von Ingres - Oracle - Sybase, in: Datenbank FOKUS (1996) 1, pp. 62-72.
Contact	Prof. Dr. G. Knolmayer Email:knolmayer@ie.iwi.unibe.ch
Partners	Schweizerische Mobiliar-Versicherungsgesellschaft Bundesgasse 35 CH 3001 Bern Generaldirektion PTT Ostermundigenstr. 91 CH 3029 Bern