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 200 200 300 400 500 200 1,800

Costs
- Output
- Regular time = R3 per skateboard
- Overtime = R3 per skateboard
- Subcontract = R6 per skateboard
- Inventory = R1 per skateboard per period on average inventory
- Back orders = R10 per skateboard per period
They are now considering a plan that proposes maintaining a consistent level of regular-time output, primarily relying on inventory to handle fluctuations in demand while also allowing for some backlog. There is a maximum overtime rate of 90 units and subcontracting rate of 80 units for period 4,5 and 6. They plan to begin with no inventory on hand in the first period. Develop an aggregate plan and calculate its cost based on the provided information. Let's consider a consistent output rate of 200 units (skateboards). Please be aware that the projected ending inventory is set at zero. There are a total of 15 workers, and each worker has the capacity to produce 20 skateboards per period.