How are workflows triggered in sap?

Workflows can be triggered automatically by changes in the system or manually by an operator. Manually triggered workflows are good for processes that remedy a problem the operator has noticed or for dealing with a forms-based requests (E.g. my PC won't boot). Automatically triggered workflows are useful because the operator does not even have to be aware of the workflow's existence to trigger it. In addition to triggers embedded in transactions there are also generic triggering mechanisms such as a change in the status of a business object or a change in the HR data. Irrespective of how the workflow is triggered, it is linked to the business object as described in the previous answer and can be tracked easily. Because WebFlow is part of the basis system, this triggering is reliable and easy to implement.

Workflows may be triggered by events but this is not essential. The event-handling makes it easy to trigger workflows from transactions and system changes without you having to make modifications. If you are creating your own report or transaction which triggers a workflow, avoid events and trigger the workflow directly with the WAPI function call. This is particularly important when triggering a workflow from outside the SAP system. This method reduces flexibility (the workflow ID is hard-coded) but increases performance if this is an issue (we're talking about 50 000 work items a day here!).

Any exception handling workflows that are intended to be triggered manually can be triggered from the system menu when viewing the relevant transaction. The SAP system has the intelligence to suggest workflows that can be triggered manually based on the authorization of the operator and the context that the operator is working in. No additional customizing is needed here.