Set up time and tear down time is performed usually once for each lot or batch of part. Set up time per price is obtained by dividing the set up time for the machine by the number of pieces produced in lot. Set up time, handling time and tear down are estimated from previous performances on similar operations. All work on a particular type of machine tool consists of a limited number of elements. These elements can be standardized, measured and recorded. This is done under Time and Motion study. Standard data are available for set up time, tear down time and handling each machining operation which takes into account speeds of cutting, feeds and depth of cut and tool travel. The actual amount of down or lost time that will occur in a particular operation can scarcely be predicted. The sum of machining time and the handling time is called ‘run time’ or ‘unit operation time’