Purchased material represents the dominant concern in distribution environments and in many manufacturing environments. The supply chain activities for purchased material reflect demands stemming from the S&OP game plans for saleable products. In addition to purchase orders for stocked material, purchase order variations include drop shipments, special orders, kit items, and outside operations. Sourcing and agreement information can be defined, including preferred and approved vendors , vendor agreements about prices and discounts , purchase quotes, reverse auctions, and blanket purchase orders. Planning calculations help coordinate procurement activities by communicating suggested action messages on a requisition worksheet. These messages suggest new purchases and changes to existing purchase orders, such as rescheduling or canceling an order. The case studies highlight variations in purchase order processing, including multistep receiving procedures and the use of vendor schedules.