Duck Lovers Unlimited (DLU) Inc. assembles specially configured light jet aircrafts for airborne duck hunting. The quarterly demand forecasts for the upcoming fiscal year are:

It takes an average of 2500 direct labor hours to assemble each aircraft. Currently, 48 full-time production workers are employed by DLU, working a single 8-hour shift each day. As of now, there is no inventory of completed or semi-finished units. Demand backlogging is possible, at a cost of $9,500/quarter for each aircraft backordered. Under-time or overtime work may be resorted to, the latter being restricted to 4 hours per day for each worker. The average regular time labor wage rate is $18/hour, with a 50% premium for overtime work. Finished goods inventory holding costs are $16,000/unit/year. The holding and backlogging costs, if any, are charged to end-of-quarter finished goods inventories and backorders, respectively. The workforce size can be varied through hires or layoffs (done at the beginning of any quarter) at $1,100 or $925, respectively, per worker. For simplicity, assume that there are about 500 regular-time hours in a quarter. Material and overhead costs per aircraft amount to $20,000. DLU does not wish to have any backorders at the end of the fiscal year.

(a) Develop, in the tabular format shown below, an aggregate sales and operations plan (SOP) for DLU, employing the minimum possible workforce size, keeping it constant throughout the year (after initial hires or layoffs, as necessary) and allowing no overtime, backorders, or part-time employees. Summarize your SOP in the table below and compute the resulting total relevant cost for the next four quarters.

(b) Removing all the restrictions specified in part (a), develop a feasible chase SOP for DLU. What is the total relevant cost now?

Quarter Forecast (units): 2 4 17 15