Abstract: In this contemporaneous world, in order to fulfill consumers’ limitless mandate for developing density, advancing functionality, and dominating power consumption, the dimensions and operating voltages of computer electronics are lessening day by day. This reduction in size raises sensitivity to radiation dramatically triggering soft error. If the radiation is large enough then even a single radiation may cause a stored data bit to be corrupted and flipped [1]. This deviation in the data values is termed as data errors. The consequence of the deviation is very vital on critical variables which consequently modify the system control flow prompting system failure [2]. Critical variables are characterized as those having high sensitivity to errors. This paper concentrates on critical variables for developing and employing error detectors to keep them away from data errors and provides high coverage for errors in any data value used in the program. The development is performed automatically through the support of backward slice of a program. The error detectors yield the method of checking expressions optimized in each control flow path surveyed at runtime [3].