A workflow must pass validation before you can put it into production. You can manually validate a workflow at any time during the design session. Workflow Automation automatically validates a workflow when you save the workflow or attempt to put a workflow revision into production.
NOTE:
Due to the complexity of some workflows, it may not be possible to complete a workflow in one design session. You can save the workflow and return to it at a later time to perform validation.
The Workflow Designer checks that you have a Start of Workflow activity, an End of Workflow activity, and that the connectors are properly attached. The Workflow Designer does not validate workflow logic.
For more information about putting a workflow into production, see Putting a Workflow Revision into Production.