Changeovers

Changeover refers to the process of switching a production line, machine, or work center from producing one item or batch to another. It includes the time required to shut down, adjust tooling, replace fixtures, clean, adjust settings, and verify that the new setup is ready for production. Changeovers are common in manufacturing environments with frequent product changes and small to medium batch sizes, as well as in packaging, printing, and food processing.

Changeovers are commonly categorized as internal or external. Internal changeovers require stopping the equipment during the change; external tasks can be performed while the machine runs, often by pre-staging materials and tools, so the actual shut-down time is minimized. The goal is to reduce internal time and maximize external preparation.

One influential approach is SMED, or Single-Minute Exchange of Die, developed in lean manufacturing. It aims to reduce setup time to less than 10 minutes by separating internal and external steps, converting as many steps to external while the machine is running, and streamlining remaining steps. Techniques include standardized tools, quick-change fixtures, parallel work, and pre-assembly.

Reducing changeover time increases equipment availability, enables smaller batch sizes, improves responsiveness, and enhances delivery performance. It is reflected in metrics such as overall equipment effectiveness (OEE) and takt time alignment. However, improper changeovers can introduce quality risks if the new setup is not validated.

While rooted in manufacturing, changeover concepts are applied in services and support processes that require switching between tasks or configurations.