The main aim of this paper is to minimize the failure of the IC engine components by analyzing the failure rate of the components in IC engines and also to find out failure range for each and every component has been determined. For doing so the real time failure data's and their life periods for each components in the IC engines has been analyzed, from these data's the amount of defects in their original production activities and also defects after the design modification work also been concluded, not only the rejections carried out in the production the accepted I.C. engines has been found out. Based on the failure data's the criticality for each component has been ranked out and risk priority number (RPN) and the corresponding transformed scale for each component has been sorted.