Build to Order is a production approach where products are not built until a confirmed order is received. The end consumer determines the time and number of produced products. Ordered products are customized to meet the design requirements of an individual, organization or business. Production orders can be generated manually, through inventory and production management programs, such as configuration system. BTO is the oldest style of order fulfillment and is the most appropriate approach used for highly customized or low volume products. Industries with expensive inventory use this production approach. Made to order products are common in the food service industry, such as at restaurants.