A standard costing system generates rate & volume variances by design. Standards are entered into the system, actual is reported into the system and variances are created. Because standards are used to value inventory and cost of goods sold, actual variances are reported on the income statement to bring the financial statements back to actual.
If you are in the accounting department in a lean manufacturing company, and your company uses a standard costing system, it is inevitable that the accounting department will be faced with confronting how its standard costing system is being used. I stress the term inevitable, because based on my own experience both as a CFO