Access SAP Workflow via BRF+

Hi Experts,

Can anyone explain to me what is the relation between sap business workflow and BRF+?

I am interested to know how we can access the workflow decision table via BRF+?

And if we access the workflow via BRF+, that means we modify the workflow it self? or we create kind of variant or different version?

Thanx,

John

PS: I have checked most of the articles in SDN but I was not able to find the answers to my questions.