Transitions represent allowable changes between states. One of the first steps in the development of an Object State Transition Network (OSTN) is to identify all possible states in which the object can exist.
Though a real-world object often evolves through a continuum of states, an OSTN diagram focuses on those distinguished states that are of particular interest to the domain expert. For each of these states, the OSTN diagram supports the specification of:
▪the conditions that characterize the state
▪the conditions that will permit a transition into the state (entry conditions)
▪the conditions that need to hold for the object to transition out of the state (exit conditions)