I'd like to be able to determine whether a ticket-comment was made by a user who was an agent or admin at the time of the comment. Ticket comments currently include the user_id of the user making the comment, and each user has a role (end-user, agent or admin), but as people change roles within our organization or leave altogether, the role field on a user becomes an unreliable indicator of the status of a comment-author at the time of the comment.
Please include either a new table for the role-history of a user (e.g. a user_id, timestamp, role tuple) or a field to ticket_comment indicating the role of the user making the comment at the time of the comment.
Determining the role of a commenter helps us measure the number of agent replies, earliest agent reply, time between agent replies, etc.