How to determine if a Peoplesoft security role is still being used or not

I am have been given the task of going through our Peoplesoft roles (#225) and trying to determine if the role is still being used.

• Is there a way to deactivate/disable the role?
• Is there a last used/access date that I can query?

I would be very appreciative for anyone experiences/suggestions on the best way to tackle this.

Thanks in advance for your comments.