When to Investigate Variances
Managers realize that a standard is not a single measure but rather a range of possible
acceptable input quantities, costs, output quantities, or prices. Consequently, they expect
small variances to arise. A variance within an acceptable range is considered to be an “in
control occurrence” and calls for no investigation or action by managers. So when would
managers need to investigate variances?
Frequently, managers investigate variances based on subjective judgments or rules of
thumb. For critical items, such as product defects, even a small variance may prompt
investigations and actions. For other items, such as direct material costs, labor costs, and
repair costs, companies generally have rules such as “investigate all variances exceeding
$5,000 or 25% of the budgeted cost, whichever is lower.” The idea is that a 4% variance
in direct material costs of $1 million—a $40,000 variance—deserves more attention than
a 20% variance in repair costs of $10,000—a $2,000 variance. Variance analysis is subject
to the same cost-benefit test as all other phases of a management control system.