The terms BOM and routing are familiar terms to users of standard manufacturing functions. In manufacturing, a BOM defines the raw materials, components, or subassemblies that make up an item. A routing is a set of steps for manufacturing an item.

In the manufacturing environment, the BOM and routing associated with an item are typically standard: the item is generally made in the same way. While alternates and substitutions can exist, this one-to-one relationship is illustrated by the fact that the BOM and routing associated with an inventory item typically have the same number code as the item. Manufactured item 10-400 uses BOM 10-400 and routing 10-400.

In Service/Support Management, you use BOMs and routings in a slightly different fashion, reflecting the requirements of the service environment. From a service perspective, a BOM may be a list of replacement parts for repairing or maintaining an item, or a set of items needed to perform an installation. A routing is a set of steps detailing the procedure to be followed in repairing, installing, or maintaining an item.