Can you please explain as much as possible like if I had zero Knowledge on this subject?

... 13.11 Deb Bishop Health and Beauty Products has devel- oped a new shampoo, and you need to develop its aggregate schedule. The cost accounting department has supplied you the costs relevant to the aggregate plan, and the marketing depart- ment has provided a four-quarter forecast. All are shown as fol- lows: QUARTER 1 2 3 4 FORECAST 1,400 1,200 1,500 1,300 Previous quarter's output Beginning inventory Stockout cost for backorders Inventory holding cost Hiring workers Layoff workers Unit cost Overtime Subcontracting COSTS 1,500 units O units $50 per unit $10 per unit for every unit held at the end of the quarter $40 per unit $80 per unit $30 per unit $15 extra per unit Not available Your job is to develop an aggregate plan for the next four quarters. a) First, try hiring and layoffs (to meet the forecast) as necessary. b) Then try a plan that holds employment steady. Note for b): - i) Use the average quarterly forecast as the level output rate per quarter. ii) Shortage (or stockout) is allowed and will be fulfilled at in the next period. iii) Capacity adjustment cost from previous quarter to quarter I needs to be included