Scenarios

A scenario is an ordered set of interactions between partners, usually between a system and a set of actors external to the system. It may comprise a concrete sequence of interaction steps (instance scenario) or a set of possible interaction steps (type scenario).

Scenarios were first used in the field of human-computer interaction. Stirred by the work of Jacobson, scenarios received considerable attention in requirements engineering.

Jacobson coined the term use case for type scenarios and later introduced it into UML. Hence, this term is widely used today. In Jacobson's terminology, scenarios are always on the instance level. In our research, we treat the terms type scenario and use case as synonyms.

We are investigating the problem of structuring and integrating scenarios. We represent scenarios with statecharts or with a structured textual notation that can easily be transformed into a statechart. For scenario integration, we exploit the structuring and decomposition features that are inherent to statecharts [Glinz 2000b, Glinz 1995].

We have also developed a more elaborate way for depicting and representing scenario structure and dependencies [Ryser and Glinz 2001].

We are working on the problem of integrating scenario models and object or class models in requirements specifications. We investigate both a tight integration (see the ADORA project) and a lightweight integration that aims at making the models consistent [Glinz 2000a].

We have conducted a study on the use of scenarios in industrial projects [Arnold et al. 1998].

Ryser, J., M. Glinz (2001). Dependency Charts as a Means to Model Inter-Scenario Dependencies. In G. Engels, A. Oberweis and A. Zündorf (eds.): Modellierung 2001. GI-Workshop, Bad Lippspringe, Germany. GI-Edition - Lecture Notes in Informatics, Vol. P-1. 71-80.

Glinz, M. (2000a). A Lightweight Approach to Consistency of Scenarios and Class Models. Proceedings of the Fourth IEEE International Conference on Requirements Engineering. Schaumburg, Illinois. 49-58.

Glinz, M. (2000b). Improving the Quality of Requirements with Scenarios. Proceedings of the Second World Congress on Software Quality. Yokohama. 55-60.

Glinz, M., N. Schett (2000). Preliminary Validation of a Lightweight Approach to Consistency of Scenarios and Class Models. Technical Report 2000.02, Institut für Informatik, University of Zurich.

Arnold, M., M. Erdmann, M. Glinz, P. Haumer, R. Knoll, B. Paech, K. Pohl, J. Ryser, R. Studer, K. Weidenhaupt (1998). Survey on the Scenario Use in Twelve Selected Industrial Projects. Technical Report AIB 98-07, RWTH Aachen.

Glinz, M. (1995). An Integrated Formal Model of Scenarios Based on Statecharts. In Schäfer, W. and Botella, P. (eds.) (1995). Software Engineering - ESEC '95. Proceedings of the 5th European Software Engineering Conference, Sitges, Spain. Berlin, etc.: Springer (Lecture Notes in Computer Science 989). 254-271.