Implementing Lean Six Sigma 4.0 and Demand-Driven Material Requirements Planning for Enhanced Maintenance, Repair, and Operations Inventory Efficiency and Cost Reduction

Abstract The purpose of this research is to reduce the value of maintenance, repair, and operations (MRO) inventory (active and slow categories) by five percent in a mining sector organization. To achieve this aim, the research team uses an action research framework with a Lean Six Sigma (LSS) 4.0 approach and demand-driven material requirements planning (DDMRP) concepts. According to the simulations conducted in this LSS 4.0 project, the value of MRO inventory could be reduced by 51%, and the service level could improve to 88%. This project has several limitations, such as not including vital and emergency MROs, not including other operational regions with different MROs, conducting the simulation at the family level instead of the stock-keeping unit (SKU) level, and not fully implementing. Using theoretical and practitioner approaches, this paper contributes to the body of knowledge about how Industry 4.0 technologies could be used in continuous improvement projects, demonstrates the importance of inventory management in MRO, validates the importance of success factors mentioned in the literature, and offers a different approach where LSS could be combined with other methodologies, such as DDMRP.