The basic index which is used the occasion where you measure whether the capital which it drops has borne how much profit. Profitability of enterprise and operational efficiency of the dropping capital in business are shown.

As for basic system with as follows, as for ROI it means the investment matter which is superior in large extent profitability.

ROI =
Profit
Investment
×100

ROI in accounting,withthe index whichresemblesto ROA / ROE etc., the investor (the shareholder) is used in order to judge the profit characteristic of the enterprise which is the investee from point of view, from numerical value of the balancing of accounts book as description below is calculated with formula.

ROI =
This term operating profit + cost accounting
Capital stock + possession interest debt
×100

As for the basic shape of ROI because it is simple, there are various variations, with cash flow as a base business section and individual project, they are utilized even in appraisal of the investment anti- effect in the individual commodity.

Especially, recently, from the fact that it is designed in such a way that measuring the investment anti- effect regarding the IT investment of enterprise is required, ROI regarding IT investment (IT-ROI) also the needs which are deduced have strengthened.

In IT investing, "investment" is not only early investment,the cost"of TCO " and so on is included. In addition also "the profit" always seems like the "business profit", because just something which is easy to understand, a some methodology which appraises the IT investment effect becomes necessary.