The collection of processes associated with ordering materials (raw materials, semi-finished products, finished products, goods, merchandize) and/or services for specific orders. The intention ofSource-to-Orderis to order materials for explicit -identifiable- downstream demand: Demand isnotaggregated. A specific reference or customer order detail is exchanged with the supplying party, attached to or marked on the product, recorded in the warehousing orEnterprise Resource Planning Systemin order to track individual deliveries. Source-to-Orderis aMTOprocess.