A composition algorithm for reusable workflow models

The use of model composition algorithms is becoming more wide-spread. For example, model composition can be applied in the context of Software Product Lines when integrating optional features, or when reusing models in multiple contexts. While composition of structural models is relatively straightforward, behavioural composition is more challenging. In this paper, we propose a composition algorithm for workflow-oriented (modelling) languages, and show how the same algorithm can be reused to compose models expressed with two different requirement modelling languages: Use Case Maps (UCM) and Use Case Specifications (UCS). Despite UCM being a graphical language and UCS being a textual language, both modelling languages model software/system functionality by describing a series of responsibilities or steps. We discuss the effectiveness of our algorithm using an example and a case study.