We've been mostly exploring the static side of UML modeling, with the exception of use cases, which model behavior on a fairly abstract level. Now it's time to dig deeper into the dynamic side of the UML.
This chapter explores the following three areas:
The various ways by which object behavior is initiated
The UML's action model, which defines the individual, primitive functions that serve as the lowest (in other words, least abstract) level of behavior specification
Activities, which provide control and data sequencing constraints among actions ‚ as well as inputs and outputs for those actions ‚ and nested structuring mechanisms for control and scope