A.3 State Diagrams

A state diagram is used to emphasize the state of objects and their transitions to those states. A state is a condition that an object occupies at some point in its lifetime. An object can be transformed into many different states in its lifetime. The objects transform into a state if some condition is met, some action is performed, or some event has taken place.

Figure A-10. State diagrams show the states and transitions of an object during its lifetime. A state diagram has an initial state and a final state. A state has several parts . States can also be a composite of other states or even another state diagram. Substates that execute in parallel within a single entity are called concurrent substates .