Three findings stand out from the empirical analysis. First, sustainability-weighted features improve forecast accuracy by over 40\% relative to the moving average baseline, which translates directly into tighter safety stocks and lower holding costs. This finding suggests that environmental data sources routinely collected for regulatory reporting can be repurposed as predictive signals at no additional cost. Second, the Pareto analysis reveals that sustainability and cost are not intrinsically in tension. Emissions can be cut by up to 15\% at a cost increase below 2\%, and the optimal trade-off point reduces both dimensions simultaneously. This challenges the conventional view that green initiatives necessarily erode operating margins. Third, the circular economy engine makes end-of-life decisions tractable at scale. Classifying 200 part types into structured pathways rather than defaulting to disposal enables maintenance managers to extract residual value systematically, contributing to the 30.6\% waste disposal reduction reported in Table~\ref{tab:inventory_results}. From a managerial standpoint, the framework implies that a carrier operating 100 aircraft could realise annual savings in the order of \$800,000 while cutting carbon emissions by more than 400~tonnes -- a meaningful contribution to IATA's decarbonisation roadmap.

The empirical analysis yields three key insights. First, incorporating sustainability-weighted features enhances forecast accuracy by more than 40% compared to the moving average baseline. This improvement leads directly to reduced safety stock requirements and lower holding costs. The results indicate that environmental data already gathered for regulatory compliance can serve as valuable predictive indicators without incurring additional expenses. Second, the Pareto analysis demonstrates that sustainability goals and cost efficiency are not inherently conflicting objectives. Companies can achieve emissions reductions of up to 15% while experiencing cost increases of less than 2%. The optimal balance point actually improves performance across both metrics simultaneously. This finding contradicts the widespread belief that environmental initiatives inevitably harm profit margins. Third, the circular economy framework enables practical end-of-life decision-making on a large scale. By categorizing 200 component types into organized pathways instead of automatically disposing of them, maintenance teams can systematically recover remaining value. This approach drives the 30.6% reduction in waste disposal documented in Table~\ref{tab:inventory_results}. From a practical management perspective, the framework suggests that an airline with 100 aircraft could achieve annual cost savings of approximately $800,000 while reducing carbon emissions by over 400 tonnes. This represents a substantial step toward meeting IATA's decarbonization targets.