ROA has been used as the measure of financial performance.ROA is defined as the after-tax net operating income divided by the total operating assets.Net operating income is computed as the operating earning before income and taxes,before extre-ordinary items, and prior-period adjustment.prowess database of CMIE has an item called EBIT (earnings before interest and tex) prior to extra-ordinary items. It has used as a proxy for net operating income.Marginal tax rate has been used to compute ROA. While computing operating assets, capital work-in-progress has been excuded.