For manufacturers, maintaining operational efficiency often hinges on the performance of machinery, some of which may be decades old. The challenge of sourcing and storing spare parts for these legacy systems is a significant logistical and financial hurdle. Manufacturers employ a multi-faceted strategy to address this. A primary approach is proactive lifecycle management, where companies forecast the lifespan of critical components and procure a final batch of parts before a production line is discontinued. This "last-time buy" ensures a long-term supply. Furthermore, many forge strong partnerships with original equipment manufacturers (OEMs) who may continue to produce limited runs of essential parts or provide blueprints. The rise of additive manufacturing, or 3D printing, has been a game-changer; it allows for the on-demand production of obsolete parts directly from digital models, drastically reducing the need for physical inventory. Additionally, a robust network of aftermarket suppliers and specialized vendors fills the gap by reverse-engineering and fabricating parts no longer available from the OEM. Some companies also implement cannibalization policies, decommissioning non-critical older machines to harvest parts for maintaining essential ones. Through this combination of strategic planning, technological innovation, and supply chain collaboration, manufacturers effectively overcome the spare parts inventory challenge, ensuring their valuable older assets remain productive for years to come.