The following measures are sometimes proposed as indicators of earnings quality. Be careful about them.
(Sometimes the denominator is net income.) As chapter 3 informed, free cash flow is not an indicator of value added and thus not a good measure to challenge accrual operating profit. For example, free cash flow is low if a firm in investing in (quality) assets to earn profits in the future. That makes the cash conversion ratio look bad while the firm is investing for value.
This inverse of the asset turnover (ATO) is an important driver of value, as in chapter 7. It is sometimes also viewed as a measure of efficiency of NOA in generating revenue and thus a quality indicator. But, due to conservative accounting for investment, NOA does not include all assets generating revenue, for example, brands and R&D assets. So, if R&D investment is delivering a lot of revenue but is not in NOA, the consequent low Net Operating Assets-to-Revenue ratio looks like the NOA that are on the balance sheet are being used efficiently. Maybe not.