The usual method of determining the productivity of such clinics is the monthly report, listing patient visits, fillings, extractions, prohylaxis, and prosthetics. An alternative to assessing the efficiency of dental services is based on time unit values, a modified time motion system for tracking efficiency that also credits the dentist with time spent on services such as consulting, taking x-rays, administering anesthetics, writing prescriptions, and placing and removing sutures. This method is used by the Michigan Department of Corrections. It involves the assignment of time values and unit factors to 51 common dental procedures on a weekly form. These figures, in conjunction with the number of hours in a clinic day, number of patients seen, and number of dentists, provides a means of determining the effectiveness and productivity of the clinic. When figures fall below an expected threshold, it usually indicates a problem in clinical utilization. Such problems may be due to inadequate patient access, equipment, personnel, or supervision.