1. Under which conditions would a plant manager elect to use a fixed-order quantity model as opposed to a fixed-time period model?

Daily demand for a product is 10 units, with a standard deviation of 3 units. The review period is 30 days, and the lead time is 14 days. Management has set a policy of satisfying 98 percent of demand from items in stock. At the beginning of this review period, there are 150 units in inventory. How many units should be ordered?

2. Ray's Satellite Emporium wishes to determine the best order size for its best-selling satellite dish (Model TS111). Ray has estimated the annual demand for this model at 1,000 units. His cost to carry one unit is $100 per year per unit, and he has estimated that each order costs $25 to place. Using the EOQ model, how many should Ray order each time?

3. The Model J Wagon is to be assembled on a conveyor belt. Five hundred wagons are required per day. Production time per day is 420 minutes, and the assembly steps and times for the wagon are given in Exhibit 8.9A. Draw precedence diagram, calculate cycle time, find the balance that minimizes the number of workstations, subject to cycle time and precedence constraints, and draw proposed grouping workstations with designed task and calculate efficiency.

4. Western National Bank is considering opening a drive-thru window for customer service. Management estimates that customers will arrive at the rate of 15 per hour. The teller who will staff the window can service customers at the rate of one every three minutes. Assuming Poisson arrivals and exponential service, find Utilization of the teller, Average number in the waiting line, Average number in the system, Average waiting time in line, Average waiting time in the system, including service.