What is aggregate planning and how long is the planning horizon? What demand and capacity manipulators do we use? A manager has prepared a forecast of expected aggregate demand for the next six months. Develop an aggregate plan to meet this demand given this additional information: A level production rate of 100 units per month will be used with regular output. Backorders are allowed, and they are charged at the rate of $8 per unit per month. Inventory holding costs are $1 per unit per month. Determine the cost of this plan if regular time cost is $2 per unit and beginning inventory is zero. Expected demand: 80,100,120,120,100,80