Other nonfinancial performance measures turn up in JIT environments. These provide signals of overall processing efficiency by measuring the extent to which the factory has achieved the JIT ideal of minimum inventories or its corollary, maximum material velocity. Examples of such measures are the average number of units in process, the maximum number of units in process during a period, and total leas time between receipt of a customer order and shipment. One popular measure of this type is manufacturing cycle efficiency, which measures processing time as a fraction of the total time a unit is in the factory. It is calculated as: