A structured list of the items used in making a parent assembly that reflects the actual production process in terms of timing and quantities consumed. It is constructed in conjunction with the routing, which describes the individual production steps and rates used. A BOM may optionally include information relating to backflushing, use of alternate and optional components, tie between components and the operations that use them, and other data. BOMs are used by the MRP function to calculate component requirements when given a parent demand, and in building product costs. (Synonym: product structure, recipe, formulation, ingredients list)