A changeover is the act of converting a process or machine from one type or design of work to another. Also referred to as setup, changeovers are required when one part has finished running on a machine and another part of different design is required to run on the same machine requiring different tooling or processes. The changeover time is the measured time that elapses between the end of the first run, and the beginning of the subsequent run that results in the first good part. Changeovers can involve changes in tooling or fixtures like dies on press machines, or can be related to the worker, where gaining knowledge of the next run can result in reduced changeover time.
Changeovers are most closely related to Single Minute Exchange of Dies (SMED), which is a measure of how quickly and accurately a changeover is performed. Excessive changeover times usually lead to excessive production cycle times, and can inhibit the quest for single-piece flow, and/or increased inventory levels.