A technique for managing complexity of use cases for large complex embedded systems

Modern computer based systems are becoming increasingly complex ensembles of hardware and software; thus adding more challenges to the software requirements engineering process. Although it is well acknowledged in the literature that the use case technique provides a successful requirements engineering tool, there is very little published material on how the use case technique deals with large complex systems. This paper proposes an extension for the use case technique by defining a hierarchical framework for the use cases of large complex embedded systems, and giving some guidance on how to identify actors on different levels. The technique is a result of practical experience with an industrial real-life case study from the aerospace industry.