Example 3 Yam Co is involved in the processing of sheet metal into products A, B and C using three processes, pressing, stretching and rolling. The factory has 50 production lines each of which contain the three processes: Raw material for the sheet metal is first pressed then stretched and finally rolled. The processing capacity varies for each process and the factory manager has provided the following data: Processing time per metre in hours Product A Product B Product C Pressing 0.50 0.50 0.40 Stretching 0.25 0.40 0.25 Rolling 0.40 0.25 0.25 The factory operates for 225,000 hours. Identify the bottleneck process and explain why this process is described as a ‘bottleneck’.