Event trigger or Call function module direct trigger WF

Hi Guru,

1. Which way is best way to trigger the workflow from a transaction (ex. VA01 or VA02) user exit?

2. If I am start WF direct via FM SAP_WAPI_START_WORKFLOW in user exit USEREXIT_SAVE_DOCUMENT in tcode VA01/VA02, the workflow will start after commit work take place in VA01/VA02 or before commit work take place? Is there any data consistence issues if I am call WF directly from USEREXIT_SAVE_DOCUMENT? I know this user exit called before commit work take place so I still can verify some of the data before sales document has been saved.

Thanks,