Some products are produced in such a manner that individual units are not identifiable throughout the process. Examples include the manufacture of paint, the refining of oil, and the canning of food. The cost of a completed gallon of paint or oil or can of vegetables is determined by a series of calculations as the product moves through the various production processes. Costs are accumulated for each production department (or manufacturing process) each period and are allocated to the production units processed during that period in each department. The costs accumulated for production units that are transferred out of one department are considered to be costs of materials added to the subsequent manufacturing process. Costs accumulated for production units that are transferred out of the final department are considered to be costs of items added to finished goods inventory. The procedures for accounting for the flow of costs in a process cost system and the related equivalent units of production are discussed in this chapter.