What metric describes the time from completion of the last good part to the first good part of the next run?

The metric that describes the time from the completion of the last good part to the first good part of the next run is commonly referred to as changeover time. This term is used in manufacturing to indicate the duration it takes to switch from producing one product to another, including any adjustments or setups required to initiate the new production run.

Changeover time encompasses all activities necessary for the transition, such as resetting equipment, reloading materials, and ensuring that the machinery is calibrated to produce the next item accurately. This metric is crucial for efficiency in operations, as reducing changeover time can significantly improve overall productivity and lead to decreased downtime between runs.

While set-up time and start-up time are related concepts, they generally refer to specific segments of the changeover process. Set-up time usually refers specifically to the adjustments made before production starts, while start-up time pertains to the period it takes to begin production after set-up is complete. Takt time, on the other hand, is a metric used to schedule production based on customer demand, and does not specifically measure the time between production runs. Thus, changeover time is the most accurate choice in this context.