In EPDM 2015 SP2, I have a variable that will be have a Yes/No value. I put a text box on the card with a value of NO to start. At a transition in the workflow I have an action type of Set Variable for the specific variable and the value is set to YES. The variable is not used in any file, just the card, and is only used as a trigger to move files down one transition or another depending on the value.
When I move a file through the transition with the action the value does not change to Yes (the card still shows a NO) so later on when it comes to the transition with conditions it always reacts as if it is a NO.