Continuing my thoughts about the MDA Conference I want to make some remarks about (Kalnis, Celms, Kalnina, & Sostaks, 2009).

It was rightly stated in the presentation, that UML sequence diagrams are insufficient to model behavior and that a new kind of modeling method is needed. Also the lack of a modeling method for operations of a class was obvious – nobody knows in which sequence they have to be called – if not prose does describe it. Therefore a new modeling method was proposed, that displays classes as swim lanes containing the operation definitions of the class as nested activities containing actions. In this “action language” sequences can be expressed by arrows between actions of one swim lane and other swim lanes.

In my opinion this idea points into the right direction. Actions / operations must be set into relation with regards to their mutual constraints and a simple graphical notation for this is needed.

I did not understand however why it is necessary to distinguish between operations and actions, because in my opinion the actions in this method reveals details of the inner structure of the operations, which is in my opinion not relevant. Furthermore in my opinion the flow based modeling (arrows) leads into a model explosion, if big examples (business use cases) are modeled.

In my opinion the suggestion of (Engels, 2009) was more appropriate to the task in this aspect.

References

Engels, G. (2009). Keynote: Automatic generation of behavioral code – too ambitious or even unwanted? In M. Aksit, E. Kindler, A. McNeile, & E. Roubtsova (Hrsg.), First European Workshop on Behaviour Modelling in Model Driven Architecture (BM-MDA). Amsterdam, The Netherlands: Centre for Telematics and Information Technology Workshop Proceedings.

Kalnis, A., Celms, E., Kalnina, E., & Sostaks, A. (2009). Behaviour Modelling Notation for Information Systems Design. In M. Aksit, E. Kindler, A. McNeile, & E. Roubtsova (Ed.), First European Workshop on Behaviour Modelling in Model Driven Architecture (BM-MDA) (pp. 29-40). Amsterdam, The Netherlands: Centre for Telematics and Information Technology Workshop Proceedings.