Purchase of Consumable Material

When we refer to consumable material, the term basically means materials which are not kept in stock but instead procured directly for an account assignment object. For example, a printer purchase for the purchasing department. In this case, the consumable material is the printer, and the account assignment object is the Purchasing Cost Centre.
It is optional for a consumable material to have a master record. Depending on the business scenario, if there is a need to create a material master for consumable material, then SAP offers 2 material types for this.

1. Non-valuated material (UNBW). This type of material is managed on a quantity but not on a value basis. This makes sense for low value materials but keeping track of stock is a must.
2. Non-stock material (NLAG). This type of material is not managed on both quantity or value basis. It is only used for frequently ordered items such as stationaries.

The key difference between a stock material and a consumable material is that, stock materials will be kept in stock and is valuated. This means that, every time you do a goods receipt for a stock item, your warehouse quantity increases and your balance sheet inventory account increases as well. The item is bought and stored in the warehouse first. Only when it is needed, then it is charged or consumed to the respective account assignment, such as Cost Centre, Production Order, Work Order, etc.

Consumable material on the other hand, is where we purchase a material (it can be a stock material as well), but for a specific purpose. For example, buying a printer for purchasing cost centre. This is an example of a consumable material purchase and this is why we need to enter the Account assignment at this point, since we are not storing it in the warehouse. So, SAP needs to know where will it be charging to during the Goods Receipt stage, hence why it is mandatory to have the account assignment in the Purchase Order stage. In this case, in the Purchase Order, we can enter a Printer Material code, or just enter a Short Text. For repeat purchases, it is recommended that we create a Material Master so that we do not have to key in all the necessary details over and over again. 

The following figure lists the most important difference between a Stock material and a Consumable material.

Stock Material		Consumable Material
Necessary to enter material		Possible but not necessary
Account Assignment category not required		Account Assignment category required
Goods Receipt mandatory		Goods Receipt optional
Postings done to stock accounts		Postings to consumption accounts
Material master updated with quantity, value and consumption		No value update, however, quantity and consumption update is possible
Adjustment of moving average price