Question: A plastic injection molding plant will be built to produce 6 million molded parts per year. The plant will run three 8-hr shifts per day, 5 day/wk, 50 wk/yr. For planning purposes, the average order size = 5000 moldings. average changeover time between orders = 6 hr, and average molding cycle time per part = 30 sec. Assume scrap rate = 2%, and average up-time proportion (reliability) per molding machine = 97%, which applies to both run time and changeover time. How many molding machines are required in the new plant?