Assignment:
A factory makes women's blouses in a traditional batch flow process. Making one of these blouses requires five distinct sewing operations that must be done in sequence. There are no set ups. The first two of these operations each take two minutes per blouse; the third and fourth each require one minute per blouse; and the fifth operation requires three minutes per blouse. Any of these five operations can be done on any sewing machine in the factory. In the traditional batch flow process, blouses are sewn in batches of 100. A batch moves to the next operation only when the operator has completed the entire batch. In this batch flow process, in steady state, what is the minimum throughput time for a batch to complete all five operations? In the traditional batch flow process, the factory has 70 workers and has been producing an average of 37.3 batches per 480-minute shift.
On average, each worker has 2 batches at his/her station (working on one and with one batch waiting). What is the average throughput time for a batch? Management decided to create a new experimental "cell" for a certain family of similar blouses. The new cell was set up with five fully cross-trained workers and five general purpose sewing machines. A material handler is assigned to bring batches of 100 blouses to the cell as needed, and take them away when completed.
As one batch was being completed, workers immediately began the next batch. Workers shifted tasks (operations) to prevent bottlenecks and to avoid idle time. There was sufficient room between operations for work-in-process inventory. After running this new cell for a while, the company observes that cross-trained workers need roughly 10% more time to do their tasks than workers in the traditional batch-flow environment. What is the output rate of this 5-person cell in an 8-hour day?