Activities

An activity performed by a person with the support of a software system — typically a form in a task list. The process engine assigns the work to a user and waits for its completion. Marked with a small person icon.

The generic, untyped unit of work in BPMN — a rounded rectangle with no marker icon. It states that work happens at this point without specifying how that work is performed.

An automated activity performed by software — a web service, an API call or an internal system function — with no human involvement. The engine invokes the implementation and moves on when it returns. Marked with a gear icon.

A task whose entire job is to send a message to an external participant. It completes as soon as the message is sent. Marked with a filled (dark) envelope icon.

A task that waits for a message from an external participant to arrive. The token pauses at the task until the message is received. Marked with an open (light) envelope icon.

Work performed by a person entirely outside any software system — the process engine cannot manage, track or complete it. Marked with a hand icon.

A task executed by the process engine itself, running a script defined in the model (e.g. JavaScript, Groovy). When the script finishes, the task completes. Marked with a script/scroll icon.

A task that delegates a decision to a business rules engine — typically a DMN decision table — and returns the result to the process. Marked with a table/grid icon.

A compound activity whose internal flow is defined inside the parent process. It shares the parent's data context and exists only within it. Drawn as a rounded rectangle containing its own flow (or collapsed with a + marker).

Invokes a reusable, separately defined global process (or global task). Drawn with a thick border. The called process runs with its own context and returns when finished.

A sub-process with no incoming/outgoing flows, started by an event (message, error, timer…) occurring while its parent scope runs. Drawn with a dotted border.

A sub-process with all-or-nothing semantics: either every step completes and the transaction confirms, or it is cancelled and completed steps are compensated. Drawn with a double border.

A sub-process whose inner activities have no prescribed order — performers choose what to execute, in which sequence, possibly in parallel. Marked with a tilde (~).

The marker (↻) that makes an activity repeat while a condition holds — BPMN's while/do-while on a single activity.

The marker (⦀ three vertical bars) that runs one instance of the activity per collection item, all simultaneously.

The marker (≡ three horizontal bars) that runs one instance of the activity per collection item, one after another.

The rewind marker (◀◀) that designates an activity as a compensation handler — executed only to undo a completed activity, never by normal flow.