Previous Next JavaScript must be enabled to correctly display this content

## 20.1.5 About the Workflow Runtime Engine

The Workflow Runtime Engine executes workflow instances according to the execution sequence.

When the workflow runtime engine starts a new workflow instance, the instance is based on the active version of the workflow definition unless you currently have a developer session open. If a developer session is open, the instance is based on the development version of the workflow.

Tip:

If you want to run the active version of the workflow while you have a developer session open, run your application in an incognito browser window.

When workflows execute, they begin at the start activity. The execution order of a workflow is determined by the connections and activities in the workflow, not the sequence of the items in the workflow designer tree. In cases where there are multiple options for connections (such as a case switch activity or multiple error connections), the workflow runtime engine evaluates the options based on the execution sequence specified in the property editor.

When workflow branches in Parallel Flow activities execute, they begin at the first activity in each branch, and follow the existing execution semantics of the workflow runtime engine through the branch. The sequence of execution across multiple branches is nondeterministic, and depends on the resources of the workflow runtime engine and whether activities in the parallel branches are synchronous (Execute Code, Invoke API, etc) or asynchronous (Human Task, Wait, etc). A branch is complete when the last activity of the branch is completed. When all branches of the parallel flow activity are completed, the parallel flow activity transitions to the Completed state.

Parent topic: About Workflows