An Integrated Lean Maintenance 4.0 Framework for Preventive Maintenance Redesign: Evidence from a Food Manufacturing Case Study

Maintenance management has evolved from a predominantly reactive support activity into a strategic engineering discipline that directly influences equipment reliability, operational efficiency and manufacturing competitiveness. Despite substantial advances in predictive maintenance, digital technologies and Industry 4.0, many industrial organisations continue to rely on preventive maintenance programmes that are insufficiently structured, poorly prioritised and weakly integrated with operational decision-making. This study proposes and validates an integrated engineering framework for preventive maintenance redesign that combines Lean maintenance principles, asset criticality analysis, Failure Mode and Effects Analysis (FMEA), digital information management and Maintenance 4.0 concepts within an Action Research methodology. The research was conducted in a food manufacturing company, where the existing preventive maintenance system was systematically analysed, redesigned and implemented under real industrial conditions. The proposed framework incorporated equipment criticality assessment, maintenance standardisation, digital checklists, Computerised Maintenance Management System (CMMS) optimisation and structured maintenance planning to improve maintenance effectiveness while strengthening information traceability and organisational learning. The industrial implementation demonstrated that the integrated maintenance redesign significantly enhanced maintenance planning, improved maintenance information management, increased process standardisation and supported more efficient maintenance decision-making. The findings further indicate that meaningful maintenance transformation is achieved not through the isolated adoption of digital technologies, but through their systematic integration with structured engineering methodologies and continuous-improvement principles. The principal scientific contribution of this work lies in demonstrating how established maintenance engineering methodologies can be integrated into a unified Maintenance 4.0 framework validated through Action Research in a real industrial environment. Beyond the specific case study, the proposed framework provides a transferable engineering methodology capable of supporting maintenance transformation across manufacturing sectors seeking more intelligent, resilient and data-driven maintenance systems.