Oscar Manufacturing (OM) is a company that customizing retail shelfs for shops. In the following six months, OM has the following demands in terms of linear feet : 32000 ft in month 1, 28100 ft in month 2, 33500 ft in month 3, and 34400 ft in month 4, 29000 ft in month 5 and 27800 ft in month 6. At the beginning of the first month, OM has 9000 ft of shelfing materials at hand, and OM currently has40 workers. Each worker can produce 4 linear ft of shelf per hour. of A worker is paid $22 regular wage per workhour and works up to 160 hours per month at regular wage (40 hours per week). The labor cost in production is paid in hours. Each worker can work overtime when exceeding 160 hours in a month and receives $30per hour for overtime. A worker can work up to 20 hours of overtime per month. At the beginning of each month, workers can be hired or fired. Each hired worker costs $3500, and each fired worker costs $5000. At the end of each month, a holding cost of $0.5 linear foot left in inventory is incurred. Backorder cost is $0.8 per linear foot of shelf per month. The firm can also use a subcontractor to make up some production. The subcontracting cost is $40 per hour (4 ft of shelf per-hour of output productivity) which has a maximal capacity of 2000 linear ft (500 hours) per month. For any worker hour allocation (regular, overtime or contract), pleaserun upto the nearest integer. The shelfing material costs for regular production, overtime production and contracting production are the same, thus omitted in this calculation.

Use a stable production strategy with 40 workers. To fulfill the demand, OM follows the following order: (1) inventory from the previous months, (2) overtime, (3) stockout or subcontracting depending on which one is cheaper.Note that you cannot have stockout at the end of month 6, thus, you will need to use subcontracting to make up the shortfall before you see that happens.You should consider building shelf inventory if you need that is the cheapest way to satisfy demand in later months. Please calculate the total cost of this aggregate production plan.

Month	1	2	3	4	5	6
Beginning Inventory	9000
Demand Forecast (D) in linear ft	32000	28100	33500	34400	29000	27800
# of Workers	40
Max Regular Labor Hours per month
Total hours needed to satisfy demand(use inventory first)
Max units (ft) produced by overtime hours per month
Hours used for shelfing production
Ending Inventory
# of New worker hired
# Worker laid off
Overtime units (ft)
Subcontracting units (ft)
Hiring/Training Cost $3500/per worker)
Layoff Cost ($5000/per worker)
Regular production Cost ($22/hr/worker)
Subcontracting Cost ($40/hour/worker)
Inv. Holding Cost ($0.5 /ft/month)
Stockout Cost ($0.8 /ft/month)
Overtime Cost ($30 /hr/worker)