The revenue and spending variances are computed by comparing the flexible budget amounts and the actual amounts. For example: The revenue variance of 1,750 favorable is computed by taking the difference between the actual amount ( 43,000) and the flexible budget amount ( 41,250). When interpreting a flexible budget performance report it is important to remember two things: First, to generate a favorable activity variance for net operating income, managers must take actions to increase the level of activity. Second, to generate a favorable overall revenue and spending variance, managers must take actions to protect selling prices, increase operating efficiency, and reduce the prices of inputs. 43,000 actual – 41,250 budget.