Aggregate planning is an operational activity that develops a preliminary production schedule 6-18 months in advance to minimize total costs. It forecasts sales, production levels, inventory, and backlogs. The objectives are to maximize customer service, minimize inventory investment and production changes, and maximize equipment utilization. Factors like available capacity, demand, and corporate policies must be considered. Common strategies are level plans, which keep production even, and chase plans, which match it to demand. The aggregate plan must then be broken down into specific production requirements.