1. Planners for a company that makes several models of skateboards are about to prepare the aggregate plan that will cover six periods. They have assembled the following information:
Period 1 2 3 4 5 6 Total
Forecast 100 200 300 400 500 200 1,700

Costs
- Output
- Regular time = R2 per skateboard
- Overtime = R3 per skateboard
- Subcontract = R6 per skateboard
- Inventory = R2 per skateboard per period on average inventory
- Back orders = R10 per skateboard per period

Now, they want to look at a plan that calls for a steady rate of regular-time output, mostly using supplies to handle uneven demand but still leaving some backlog. They use overtime of up to R20 and subcontracting of R10 in period 4 because they want steady work. They plan to start the first period with no supplies on hand. Using the information above, make an overall plan and figure out how much it will cost. Let's say that the level output rate is 300 units (skateboards) per period, and the normal time is 1800/6. Keep in mind that the planned closing stock is zero. There are 15 workers, and each one can make 20 skateboards in a shift.