Defining the required number of spare parts under data constraints

Abstract

Aim. The paper aims to reduce the costs associated with the post-failure downtime of equipment. This is especially relevant for industries such as oil production due to the territorial distribution of the maintained facilities and remote location of spare part storage, which leads to increased time to repair due to the wait for the arrival of the right part or piece of equipment. At the same time, there may be spare parts in stock that will not prove to be useful in the near future due to the irrational content of the stock in storage. Methods. Managing equipment spare parts usually comes down to using probabilistic methods and mathematical models for solving optimization problems, but such methods require data on the technical condition of a facility, cost characteristics, etc., that may not always be available, so a method that does not use such information needs to be developed. Results. A method is proposed for defining the number of spare items using the times-to-failure of same-type items and identifying the predicted probabilities of failures, which allows, in the absence of statistical data on the technical condition of items, minimising the downtime of equipment while waiting for spare parts.