Return on Investment (ROI) is calculated by comparing the total cost of ownership to the net benefits of ERP obtained or expected to be received from the ERP. In short, ROI is a measure of profitability that is calculated by dividing the net profit by the cost of investment.
To measure the Return on Investment (ROI), your company will have to quantify both the tangible benefits and costs of ERP implementation. After quantifying the benefits and costs, divide the Net Income by the Total Cost of Investment, and multiply it by 100.