It refers to the items which are positively and strategically prepared and stored in a warehouse by a company for the following purposes:

This inventory mainly includes assemblies and subassemblies, and is called intermediate stock goods or slack parts.

Most of them are raw-material-level items, with sharp fluctuation in price, whose lead time is originally very long. Thus by making yearly contracts, the lead time is shorter and the cost is lower.

This inventory goods are called after parts or supplementary goods, which are used for repairs of the delivered products. They are stored to relatively quickly response to the demand.

This inventory goods are called common items or standard goods because they are used for various products. This inventory makes the number of items to be controlled less, and makes production effectivity improved because items can be produced in a unified manner.

The capacities are maintained almost constant through a whole year in a factory, but significant fluctuations in demand may be observed. When some of items are produced in advance in order to equalize the production load, inventory occurs. Aside from these policy inventory items, the inventory goods which are accumulated for the production reasons are called general inventory goods or passive inventory goods.