Process
Costing
Learning Objectives
1. Describe the basic characteristics and cost flows associated with process manufacturing.
2. Define equivalent units and explain their role in process costing. Explain the differences between the weighted average method and the FIFO method of accounting for process costs.
3. Prepare a departmental production report using the weighted average method.
4. Explain how nonuniform inputs and multiple processing departments affect process costing.
Chapter Outline
1. CHARACTERISTICS OF PROCESS MANUFACTURING
Cost accounting systems should be designed to fit the nature of the manufacturing operation.
Process costing works well whenever relatively homogeneous products pass through a series of processes and receive similar amounts of manufacturing costs. A process is a series of operations performed on the product, such as mixing, molding, or packaging.
Job-order costing works well whenever products pass through a series of processes that deal out different amounts of manufacturing costs.
The manufacture of nearly any product requires three types of cost:
1. Direct materials
2. Direct labor
3. Manufacturing overhead
The job-order costing system is designed to trace costs to a job.
A process-costing system traces the costs to the process, instead of the job.
The same accounts are used in the process-costing system as in a job-order costing system with the excep tion of the number of Work-in-Process accounts. A different Work-in-Process account is required for each processing department.
The major differences between process costing and job-order costing are summarized as follows:
1. Homogeneous units pass through a series of similar processes. |
1. Unique jobs are worked on during a time period. |
2. Costs are accumulated by processing department. |
2. Costs are accumulated by individual job. |
3. Unit costs are computed by dividing the processing departments’ costs by output. In addition, output is measured in equivalent units, not in units produced. |
3. Unit costs are determined by dividing the total costs on the job-order cost sheet by the number of units in the job. |
4. The production report provides the detail
for the Work-in-Process account for each processing department. |
4. The job-order cost sheet provides the detail for the Work-in-Process account. |
A. Types of Processes
The product may flow through the processing departments in different ways including:
1. sequential processing—a method of process manufacturing in which units pass from one process to another in a sequential pattern and each unit is processed using the same series of steps.
2. parallel processing—Two examples of parallel processing are:
a. Two different products emerge from a common process, and then each flows through its own separate series of processes for completion.
b. The products flow through their separate series of processes and then eventually flow through a common department.
B. How Costs Flow through the Accounts in Process Costing
As raw materials are purchased, the cost of the materials is recorded in a Raw Materials inventory account.
As used, raw materials, direct labor, and manufacturing overhead are recorded in the Work-in-Process account.
When goods are completed, their cost is transferred from the Work-in-Process account to the Finished Goods account.
As goods are sold, their cost is transferred from the Finished Goods account to the Cost of Goods Sold account.
In process costing, each processing department has its own Work-in-Process account.
Costs transferred from a prior process to a subsequent process are called transferred-in costs.
Cornerstone 6-1: How to Calculate Cost Flows without WIP
- See Mowen and Hansen text for in-class, demo problems.
2. THE IMPACT OF WORK-IN-PROCESS INVENTORIES ON PROCESS COSTING
A. Equivalent Units of Production
- Equivalent unitsof output is the expression of a processing department’s activity in terms of fully completed units.
For example, two units that are 50 percent complete are the equivalent of one unit fully completed.
The percentage of completion is a subjective assessment. Basically, the production manager “eyeballs” ending inventory to come up with a rough estimate of completion.
- Work done on partially completed units in beginning work-in-process inventory represents prior period work. Manufacturing costs assigned to these units represent prior period costs.
Cornerstone 6-2: How to Calculate Equivalent Units of Production: No Beginning Work in Process
- See Mowen and Hansen text for in-class, demo problems.
Cornerstone 6-3: How to Measure Output and Assign Costs: No Beginning Work in Process
- See Mowen and Hansen text for in-class, demo problems.
B. Two Methods of Treating Beginning Work-in-Process Inventory
- Work done on partially completed units in beginning work-in-process inventory represents prior-period work. Two approaches used for dealing with prior period output and prior period costs found in beginning work in process are:
1. weighted average method: combines beginning inventory costs (prior period work) with costs from current period work.
2. first-in, first-out (FIFO) method: separates beginning inventory costs (prior period work) from costs of current period work.
Both the weighted average method and the FIFO method use the following general pattern to determine the cost of production:
1. Analysis of the flow of physical units
2. Calculation of equivalent units
3. Computation of unit costs
4. Valuation of inventories
a. Cost of units transferred out, and
b. Cost of units in ending work in process
5. Cost reconciliation
3. WEIGHTED AVERAGE COSTING
- The weighted average costing method combines the partially completed units in beginning work-in-process inventory with units produced in the current period to determine a weighted average equivalent units of production.
- Equivalent units of output using the weighted average method is calculated as:
Units completed and transferred out*
+ Equivalent units of production in ending work in process
= Equivalent production
*Note that the weighted average method includes the partially completed units in beginning inventory with the units that were started and completed in the current period.
- The weighted average method also merges prior-period costs with current-period costs by adding manufacturing costs in beginning work in process to manufacturing costs incurred during the current period.
- The major advantage of the weighted average method is simplicity.
Cornerstone 6-4: How to Measure Output and Assign Costs: Weighted Average Method
- See Mowen and Hansen text for in-class, demo problems.
A. Five Steps in Preparing a Production Report
Step One: Physical Unit Flow Analysis
Units to account for:
Units in beginning work in process
+ Units started during the period
= Total units to account for
Units accounted for:
Units completed and transferred out
+ Units in ending work in process
= Total units accounted for
Step Two: Calculation of Equivalent Units (Weighted Average)
Units completed and transferred out
+ Units in ending work in process × Fraction complete
= Equivalent units of output
Step Three: Computation of Cost per Equivalent Unit
Costs to account for:
Beginning work in process
+ Costs added (incurred) during the period
= Total costs to account for
Cost per equivalent unit = Total costs to account for/Total equivalent units
Step Four: Valuation of Inventories
Costs accounted for:
Goods transferred out (unit cost × equivalent units)
+ Goods in ending work in process (unit cost × equivalent units)
= Total costs accounted for
Step Five: Cost Reconciliation
Compare total costs to account for with total costs accounted for to determine that they are equal.
Tip: When you are using the weighted average method, you should ask the following question when calculating equivalent units: “What is the percent of effort provided as of the end of the period on the units worked on during the period?” This way you know you are including some work performed last period in your calculations.
Cornerstone 6-5: How to Prepare a Physical Flow Schedule
- See Mowen and Hansen text for in-class, demo problems.
Cornerstone 6-6: How to Prepare a Production Report: Weighted Average Method
- See Mowen and Hansen text for in-class, demo problems.
4. MULTIPLE INPUTS AND MULTIPLE DEPARTMENTS
A. Multiple Inputs
- Equivalent units must be calculated for each category of manufacturing input.
- Equivalent units are calculated for:
1. each type of material
2. transferred-in costs (costs from prior departments, if any) and
3. conversion costs
- For example, if ending work in process contained 1,000 units and materials were 100% complete but conversion was only 40% complete, equivalent units would be calculated as follows:
Equivalent units for materials = 1,000 × 100% = 1,000
Equivalent units for conversion = 1,000 × 40% = 400
A unit cost for materials and a unit cost for conversion would be calculated based upon the equivalent units for each.
Cornerstone 6-7: How to Calculate Equivalent Units, Unit Costs, and Value Inventories with Nonuniform Inputs
- See Mowen and Hansen text for in-class, demo problems.
B. Multiple Departments
Once the students understand how to treat different categories of inputs, extension to multiple departments is straightforward. Transferred‑in goods is simply an additional input category (a type of materials added at the beginning of the process). Besides that, a cost of production report would be prepared for each department.
Cornerstone 6-8: How to Calculate the Physical Flow Schedule, Equivalent Units, and Unit Costs with Transferred-In Goods
- See Mowen and Hansen text for in-class, demo problems.
5. APPENDIX: PRODUCTION REPORT—FIFO COSTING
This appendix goes through the production costing report using the FIFO method.
Tip: When you are using the FIFO method, you should ask the following question when calculating equivalent units: “What is the percent of effort provided during the period?” Here the emphasis is on the work performed during the period.
FIFO costing excludes the equivalent units and costs in beginning work in process (prior-period costs) from the current-period unit cost calculations.
Only current-period work and current-period costs are used to compute FIFO unit costs.
If the costs of the manufacturing inputs remain fairly stable, the weighted average and FIFO method will produce very similar results.
If the costs of the manufacturing inputs fluctuate from period to period, the FIFO method may be more useful for cost control, pricing decisions, and performance evaluation because the FIFO method concentrates on the current period’s activity.
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