Idle time variance
The idle time variance is the cost of direct-labour hours paid but not productively worked, calculated as idle hours multiplied by the standard wage rate; separating it from the efficiency variance prevents uncontrollable stoppages from.
FrameworkStandard costing and variance analysis
See it move
A machine breakdown leaves the line idle for 40 hours that workers are still paid for at the €18 standard wage rate. The idle time variance is 40 hours times €18, giving €720, always adverse because paid time produced no output. Removing it from the efficiency variance leaves a residual that reflects only genuine workforce performance.
The formula
Variables
- idle hours — direct-labour hours paid but not productively worked during the period (hours)
- standard wage rate per hour for the grade of labour concerned (€ per hour)
Always adverse (cost incurred with no productive output). Separating idle time from the efficiency variance prevents uncontrollable stoppages — machine breakdowns, material shortages — from distorting the assessment of workforce performance.