A lifecycle is formally expressed as a state machine, comprising:
States. Each state represents a stage in the lifecycle of a typical instance of the class.
Events. Each event represents an incident or indication that a progression is happening.
Transitions. A transition rule specifies what new state is achieved when an object in a given state receives a particular event.
Procedures. A procedure is an activity or operation that must be accomplished when an object arrives in a state. Each state has its own procedure. Procedures comprise actions.
The state machine is represented as a statechart diagram, as defined first in . That is, the statechart diagram is a representation of the underlying semantics defined by the state machine. ...