Draw a state diagram on a whiteboard or paper. Make sure to draw each state in a box with plenty of space between each state.
Draw each legal action between states as a line with a single arrow head. Each direction is a distinct action.
The following example is a small sample of the states you might have in your own workflow. When a new bug is entered, someone in your organization dispatches the bug to the appropriate QA engineer for review. If the QA engineer agrees that the reported behavior is a new bug, then it is sent to Development to be fixed. Development can take a number of possible actions on the bug.
Of course, these are only the developer’s claims and have yet been verified. Your workflow model might reflect these claims with the following states: Fixed?, Deferred?, Not Repro?, and Not-a-Bug? The question marks imply that these claims have not yet been verified by a QA engineer.