As a demand planning manager, your duties are to oversee the daily operations of the planning department as they analyze customer and vendor demand along the supply chain and develop ways to forecast future demand. Your responsibilities are to review purchase history, sales history, and different marketing strategies your employer has used to promote products and stimulate growth and evaluate their effectiveness. As a manager, you may oversee a unit within the department or the whole department. You train new demand forecasters and analysts, and you meet with other managers and executives to review strategies related to short- and long-term planning.