Inventory Accounting

Inventory

Definition: Inventory is an asset that is intended to be sold in the ordinary course of business. Inventory may not be immediately ready for sale. Inventory items can fall into one of the following three categories:

• Held for sale in the ordinary course of business
• That is in the process of being produced for sale

The materials or supplies intended for consumption in the production process.

This asset classification includes items purchased and held for resale. In the case of services, inventory can be the costs of a service for which related revenue has not yet been recognized.

In accounting, inventory is typically broken down into three categories, which are:

• Raw materials. Includes materials intended to be consumed in the production of finished goods.
• Work-in-process. Includes items that are in the midst of the production process, and which are not yet in a state ready for sale to customers.
• Finished goods. Includes goods ready for sale to customers. May be termed merchandise in a retail environment where items are bought from suppliers in a state ready for sale.

What is inventory?

I think of inventory as a company's goods on hand, which is often a significant current asset. Inventory serves as a buffer between a company's sales of goods and its production or purchase of goods. Companies strive to find the proper amount of inventory to avoid lost sales, disruptions in production, high holding costs, etc.

Manufacturers usually have the following categories of inventories: raw materials, work-in-process, finished goods, and manufacturing supplies. The amounts of these categories are usually listed in the notes to its balance sheet.

A company's cost of inventory is related to the company's cost of goods sold that is reported on the company's income statement.

Since the costs of the items purchased or produced are likely to likely to change, companies must elect a cost flow assumption for valuing its inventory and its cost of goods sold. In the U.S. the common cost flow assumptions are FIFO, LIFO, and average.

Sometimes a company's inventory of goods is referred to as its stock of goods, which is held in its stockroom or warehouse.

Accounting Inventory Methods

Inventory includes the raw materials, work-in-process, and finished goods that  a company has on hand for its own production processes or for sale to customers. Inventory is considered an asset, so the accountant must consistently use a valid method for assigning costs to inventory in order to record it as an asset.

The valuation of inventory is not a minor issue, because the accounting method used to create a valuation has a direct bearing on the amount of expense charged to the cost of goods sold in an accounting period, and therefore on the amount of income earned. The basic formula for determining the cost of goods sold in an accounting period is:

Beginning inventory + Purchases - Ending inventory = Cost of goods sold

When you buy inventory from suppliers, the price tends to change over time, so you end up with a group of the same item in stock, but with some units costing more than others. As you sell items from stock, you have to decide on a policy of whether to charge items to the cost of goods sold that were presumably bought first, or bought last, or based on an average of the costs of all items in stock. Your choice of a policy will result in using either the first in first out method (FIFO), the last in first out method (LIFO), or the weighted average method. The following bullet points explain each concept:

• First in, first out method. Under the FIFO method, you are assuming that items bought first are also used or sold first, which also means that the items still in stock are the newest ones. This policy closely matches the actual movement of inventory in most companies, and so is preferable simply from a theoretical perspective. In periods of rising prices (which is most of the time in most economies), assuming that the earliest units bought are the first ones used also means that the least expensive units are charged to the cost of goods sold first. This means that the cost of goods sold tends to be lower, which therefore leads to a higher amount of operating earnings, and more income taxes paid. Also, it means that there tend to be fewer inventory layers than under the LIFO method (see next), since you will continually use up the oldest layers.
• Last in, first out method. Under the LIFO method, you are assuming that items bought last are sold first, which also means that the items still in stock are the oldest ones. This policy does not follow the natural flow of inventory in most companies; in fact, the method is banned under International Financial Reporting Standards. In periods of rising prices, assuming that the last units bought are the first ones used also means that the cost of goods sold tends to be higher, which therefore leads to a lower amount of operating earnings, and fewer income taxes paid. There tend to be more inventory layers than under the FIFO method, since the oldest layers may not be flushed out for years.
• Weighted average method. Under the weighted average method, there is only one inventory layer, since the cost of any new inventory purchases are rolled into the cost of any existing inventory to derive a new weighted average cost, which in turn is adjusted again as more inventory is purchased.