1) Inventory of raw material are held to make sure that the production process is not disrupted because of shortage of raw material. The amount of raw material inventory would based upon the speed at that the raw material can be procured; the greater the speed and lower would be the stage of raw material inventory. Higher the improbability in the supply of raw material, higher would be the level of raw material inventory.
2) Work in process i.e. WIP inventories occur in the process of production. This type of inventories is also considered to as "Process Inventories". Under case of easy products the WIP inventories would be less, while in case of complex products needing various sub-processes and sub-assemblies the work in process inventory would be high.
3) Finished goods inventories are held to meet customer's need promptly. The quantum of finished services or goods inventory would based upon:
- Time needed to fill an order from the customer. If the products is of that nature which any unexpected demand can be met at short notice the level of inventories would be lower, and
- Variety of the product line: Firms selling a broad range of products normally need to invest more in finished goods.
4) Inventories are also conduct; hence the order cost is reduced.
5) Spares: An inventory of spare items which are required for the smooth running of business is also kept.
6) Transaction or Precautionary and Speculative Motives: Inventories that are held for conducting normal everyday business are termed as transaction inventory. Precautionary inventories are those inventories that are held to make sure that in case of shortage or adverse price movement, the production process will not be stopped because of the lack of inventory.