state·OMG UML 2.5.1·software, ecommerce·complexity 3/3·since v0.3.0

Checkout session with composite state and history

UML statechart for a checkout session with a composite Payment state, entry and exit activities, guards, and retry transitions.

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state-diagram·§ UML 2.5 / Harel

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Scenario

Checkout is a lifecycle, not a process list: the session can move forward, retry, or terminate depending on events and guards. A composite state keeps the external lifecycle readable while still showing the internal payment substates.

Annotation key

state Payment { ... } creates the composite state.
entry / and exit / activities document side effects on state entry and exit.
Transition labels use the UML trigger [guard] / action format.

State diagram syntax →