Dr. Peter McKenna:

Once a person has done seven years and given his or her best, that is it. A shorter period of time might allow for the possibility of a person being reappointed for another three, four or five years if that person was doing the job well and if everyone agreed. Seven years does not allow for a reappointment. It is too long. I certainly agree that appointing a person for a set period of time is far more appropriate than appointing someone until retirement.