Bhojraj Fabricators Inc. machines metal parts for the automotive industry. Under the traditional manufacturing approach, the parts are machined through two processes: milling and finishing. Parts are produced in batch sizes of $50$ ?parts. A part requires $4$ ?minutes in milling and $9$ ?minutes in finishing. The move time between the two operations for a complete batch is $10$ ?minutes.Under the lean philosophy, the part is produced in a cell that includes both the milling and finishing operations. The operating time is unchanged; however, the batch size is reduced to $5$ ?parts and the move time is eliminated.