Direct material usage variance
/What is the Direct Material Usage Variance?
The direct material usage variance is the difference between the actual and expected unit quantity needed to manufacture a product. The variance is used in a standard costing system, usually in conjunction with the purchase price variance. These variances are useful for identifying and correcting anomalies in the production and procurement systems, especially when there is a rapid feedback loop. Standards for raw materials are typically set by the engineering department and recorded in a bill of materials for each product.
The variance is most commonly used in a production environment, but can also be used in a services business where hours worked can be compared to a budgeted level.
Related AccountingTools Course
Standard Costs and Variance Analysis
How to Calculate the Direct Material Usage Variance
The calculation of this variance is as follows:
(Actual usage - Standard usage) x Standard cost per unit = Direct material usage variance
In a larger manufacturing operation, it is best to calculate this variance at the individual product level, since it reveals little actionable information at an aggregate level. The resulting information is used by the production manager and purchasing manager to investigate and correct problems.
Example of the Direct Material Usage Variance
A company manufactures wooden tables and uses wood planks as a direct material. The standard quantity of wood planks allowed for each table is 10 feet, and the standard cost per foot of wood is $5.00. The company planned to produce 1,000 tables, so the expected quantity of wood needed is:
Standard Quantity Allowed = 1,000 tables × 10 feet = 10,000 feet
However, due to inefficient cutting or increased waste, the company actually used 10,500 feet of wood to produce the 1,000 tables.
Step 1: Calculate the Variance
Direct Material Usage Variance = (Standard Quantity − Actual Quantity) × Standard Price
= (10,000 feet − 10,500 feet) × $5.00
= (−500 feet) × $5.00
= −$2,500 (Unfavorable)
Step 2: Interpretation
The negative variance indicates an unfavorable variance of $2,500, meaning that the company used 500 feet more wood than expected, which increased its costs. This might prompt management to investigate production processes, employee training, or material quality issues to prevent excessive waste.
What Causes a Direct Material Usage Variance
A usage variance can arise from any of the following issues:
An incorrect standard against which actual usage is measured. For example, a product design engineer puts an incorrect materials quantity in the bill of materials for a new product, resulting in an incorrect baseline value when the direct material usage variance is calculated.
Not changing the bill of materials after a production process or product design has been altered that should have resulted in a change in the amount of materials usage.
Problems in the production process that cause more than the normal amount of scrap.
Problems with the quality of the raw materials purchased (or damage in transit), resulting in more units of raw materials being needed than usual.