Using dependency diagrams in dynamic modelling of object-oriented systems

In defining the behaviour of a system, requirement specifications make use of a number of scenarios that are interrelated in many ways. Most of the current approaches, even though giving directions on how to translate them into state machines, treat each scenario separately. In this paper we propose a method of synthesizing state machines from multiple scenarios, with respect to the relationships among them. We propose a new type of diagrams that are able to illustrate the relationships and dependencies among scenarios. We call these diagrams dependency diagrams. We have noticed that, when trying to synthesize state machines from scenarios, different relationships between scenarios result in different state machine structures. By emphasizing these relationships, representing them and using them directly in the synthesis process, we manage to overcome this problem. We also propose a set of rules and steps for the synthesis of state machines from multiple interrelated scenarios, based on the initial scenarios and on the newly introduced dependency diagrams, as a means to properly describe the requirements specifications of a system.