The State Machine Diagram

Which state will be reached and when? Which event will trigger the state transition? In a State Machine, all states that an element will be in are described. It describes which events occur or which guards have to be in place, so that a transition in state will be made. It also describes which actions will be taken, when a transition in state occurs or a state is reached.

The diagram

The most important editing functions

	Create Initial State  Used to create start states that are directly transferred to the diagram. Describes the start of the processing of a state machine and its outgoing transition (event).
	Create Final State This button creates an final state and adds it to the diagram.
	Create State This button creates a new state and adds it to the diagram. States correspond to a situation, in which a specific guard applies. A state is entered when a transition is made of which the state is the end point. It is left, when a transition is made that leads away from the state. The symbol of a state shows its icon and its stereotype. Das Symbol eines Zustands zeigt sein Icon und seinen Stereotyp. The default stereotype of states is «State».
	Create Transition This button creates a new transition and adds it to the diagram. A transition defines a change from one state to an other. Guards can be set for transitions, which have to be in place and events, that have to occur before a transition in state occurs, and actions, that have to be taken when the transition occurs or a state is reached. The default stereotype of this kind of relationship is «TransitionType». Events, followed by guards, and actions are written over the relationship symbol.