AbstractThis paper is intended to show that the Weibull distribution can effectively be used to approximate the lead time demand in several cases of distributed demands coupled with distributed lead times. With this approximation, the computations involved are shown to be very simple, requiring no numerical or iterative procedures for determining the re-order levels or protection levels. Some pertinent properties of the Weibull distribution are summarized, and necessary tables for estimating the parameters of the Weibull distribution are given. Numerical examples are given in three cases of distributed demands and lead times and, in each case, the Weibull approximation results are compared with exact and/or other approximate results.