This paper illustrates the resampling-approach to a task of comparison of two renewal processes with application to solving one inventory theory problem. The probability of the shortage absence of inventory unit is estimated. The formula for the variance calculation of estimator of interest is presented. Obtained resampling-estimators are compared with classical ones. It is shown that considered approach could be a good alternative to classical one, taking bias, variance and mean square error of estimators into account. Numerical examples illustrate the efficiency of considered method.