In UML modeling, you can add transitions to a state machine diagram to show how an object changes state. A trigger, a guard condition, and an effect are the three optional parts of a transition. Add a trigger to a transition to show that an event must occur for a transition to initiate. Add a guard condition to a transition to show that a particular Boolean condition must be true for a transition to occur. Add an effect to a transition to show that an object performs a particular activity when a guard condition is satisfied.
Adding transitions to states and pseudostates
In UML modeling, a transition is a relationship between two states in a state machine diagram. A series of states connected by transitions describes the various states of an object and the order in which each state is entered.Adding triggers to transitions
In UML modeling, a trigger is an event that initiates a transition from one state to another. A guard condition is a boolean condition that must be satisfied for a transition to occur. An effect is the action or activity that happens when a transition occurs.Adding guard conditions to transitions
In UML modeling, a guard condition is a boolean condition that is evaluated when a transition initiates. A transition with a guard condition occurs when the guard condition is evaluated to be true.Adding effects to transitions
In UML modeling, an effect is an optional activity that occurs when a transition fires.
Parent topic: Modeling object behavior by using state machine diagrams
Related concepts
States, regions, and transitions