Criticality assessment of spare parts in the railway sector using multi-criteria analysis

Abstract

The management of spare parts inventory is a complex activity in maintenance due to sporadic demand, prolonged periods without demand, long lead times caused by imports, and high costs. The unavailability of these items can halt essential equipment and processes, while maintaining them in stock incurs high maintenance costs. In this context, this study aims to propose a systematic approach based on the Analytic Hierarchy Process (AHP) method to evaluate the criticality of spare parts in a railway company, seeking to optimize inventory management and enhance operational reliability. A total of 24 spare parts were analyzed using criteria such as quality, safety, asset criticality, and lead time. The dataset was obtained from the SAP-PM system and supplemented with expert input. The VED classification was applied, followed by an ABC reclassification based on weights determined through the AHP method. A total of 67% of the items analyzed had their classifications adjusted, reflecting a better alignment with operational priorities. Items initially categorized as critical were downgraded due to low relevance in key criteria, while others were promoted for their operational importance. The new classification demonstrated potential to optimize resources and reduce shortages of critical materials, thereby increasing asset reliability. The application of AHP proved to be effective in inventory management, enabling continuous adjustments and promoting operational improvements. This approach is replicable in other sectors and can be complemented by additional techniques, such as cluster analysis, to enhance the robustness of classifications.