State-dependent dynamic interaction modeling deals with situations in which object interactions are state-dependent. State-dependent interactions involve at least one state-dependent control object that, by executing a statechart (as described in Chapter 10), provides the overall control and sequencing of its interactions with other objects.

Chapter 9 describes basic dynamic interaction modeling, which is stateless and, hence, does not involve any state-dependent interactions. During object structuring, the objects that participate in the realization of a use case are determined. If at least one of the objects is a state-dependent control object, then the interaction is defined as state-dependent and the term state-dependent dynamic interaction modeling should be used, as described in this chapter. State-dependent dynamic interaction modeling is a strategy to help determine how objects interact with each other in dynamic interactions involving at least one state-dependent control object. In more complex interactions, it is possible to have more than one state-dependent control object. Each state-dependent control object is defined by means of a statechart.

Section 11.1 describes the steps in state-dependent dynamic interaction modeling. Section 11.2 describes how to model interaction scenarios on interaction (both communication and sequence) diagrams and statecharts. Section 11.3 gives a detailed example of state-dependent dynamic interaction modeling from the Banking System.