ICRA ratings are based on an in-depth study of the industry as also an evaluation of the strengths and weaknesses of the company. The inherent protective factors, marketing strategies, competitive edge, level of technological development, operational efficiency, competence and effectiveness of management, hedging of risks, cash flow, trends and potential, liquidity, financial flexibility, government policies, past record of debt servicing, sensitivity to possible changes in business/economic circumstances are looked into. How long does a Rating remain valid? Once the company has accepted a rating, ICRA continuously monitors the corporate and the rating is monitored till the life of the instrument. The process is known as surveillance. During the surveillance period, all changes affecting the company are taken into account and the rating, if necessary, is changed, upwards or downwards. In other words, a rating is valid during the life of the instrument unless is changed. What does the suffix + or - with the Rating mean? The suffix + or - may be used with the rating symbol to indicate the comparative position of the instrument within the group covered by the symbol. Thus MAA- lies one notch above MA+.