In accounting, process costing is a method of assigning production costs to units of output. In process costing systems, production costs are not traced to individual units of output. Costs are assigned first to production departments. Then assign the costs to units of output as they move through the departments. The process costing method is typically used for processes that produce large quantities of homogeneous products.
The process costing method is in contrast to other costing methods, such as product costing, job costing, or operation costing systems. Using the process costing method is optimal under certain conditions. Homogeneous indicates that the units of output are relatively indistinguishable from one another. If the output products are homogeneous, then it may be beneficial to use process costing. Low value indicates that each individual unit of output is not worth much. If the output products are of low value, then it may be beneficial to use process costing. If it’s difficult or infeasible to trace production costs directly to individual units of output, then it may be beneficial to use the process costing method.
For example, for the company that bottles cola, it would not be feasible or worthwhile to separate and record the cost of each bottle of cola in the bottling process. Therefore, the company would assign costs to the bottling process as a whole for a period of time. Then they would divide that overall process cost by the number of bottles produced during that period of time to assign production costs to each bottle of cola.
There are five steps in the process costing method. First, analyze the cost-flow model of the relevant inventory account to determine how much inventory was there at the beginning of the period, how much was started during the period, how much as completed during the period, and how much is left as work-in-process at the end of the period.
Second, convert the work-in-process ending inventory into a number of equivalent units produced. This means if there are 1,000 units of inventory in work-in-process, and these units are all 50% complete, then you consider this as the equivalent of 500 units produced (500 = .50 x 1,000).
Third, compute the total direct and indirect costs incurred by the production process that need to be assigned to the units completed and the units still in process. This includes the costs associated with the beginning inventory and the costs incurred during the relevant period.
Fourth, calculate the amount of cost assigned to the completed units of output and the equivalent of completed units of output still in the ending inventory. For example, if a company completed 2,000 units, and left 1,000 units half-finished, then divide the applicable costs by 2,500 units.
Follow the 5 steps for process costing.
1. Analyze inventory flow
2. Convert in-process inventory to equivalent units
3. Compute all applicable costs
4. Calculate the cost per unit of finished and in-process inventory
5. Allocate costs to units of finished and in-process inventory