Remanufacturing and LCA: A Synergistic Approach Combining Structural Reliability, Sustainability, and Life Multi-Cycle Improvement

Achieving sustainability is a strategic challenge for manufacturing. This study investigates the environmental and economic benefits of remanufacturing as a circular strategy to extend the lifetime of mechanical components while ensuring structural integrity, safety, and compliance with EU regulations. A mechanical synchronizer shaft used in the continuously variable transmission (CVT) of earth-moving machinery is analysed through a comparative life cycle assessment (LCA). Three scenarios are modelled: (i) the production of a new component; (ii) the remanufacturing of a discarded (at the end of its nominal life) component, considering the current remanufacturable rate of the inspected discarded lot (53.6%); and (iii) the remanufacturing of a discarded component assuming an improved remanufacturable rate (85%). Industrial data combined with Ecoinvent datasets are used to model cradle-to-grave impacts through SimaPro®. Results show that a remanufactured component significantly decreases the global warming potential compared with a new component. However, when accounting for the actual remanufacturable rate achievable in practice, the reduction in the global warming index is more limited, highlighting the need to improve remanufacturability to unlock the full environmental benefits. A parametric LCA model integrating the DfRem approach is developed to evaluate how increasing the initial shaft diameter enables multiple remanufacturing cycles. Over multiple remanufacturing cycles, the improved design demonstrates substantial cumulative emission savings compared with repeated production of new components, also confirming the long-term environmental benefits of remanufacturing strategies. In addition to the environmental analysis, a cost evaluation is carried out to evaluate the economic feasibility of the different scenarios. The results confirm that higher remanufacturable rates not only reduce greenhouse gas emissions but also lower overall production costs, providing a comprehensive perspective on the benefits of remanufacturing-oriented design.