Definition
The time between the last good of the previous product and the first good of the next product, including setting, first-time testing and adjustment, can be shortened by SMED.
In detail
Changeover is the total time from the last good piece of the previous product to the first good piece of the next product, including equipment adjustment, first-piece inspection, and parameter setting. It addresses the downtime waste caused by frequent switches in multi-variety, small-batch production. Unlike equipment breakdown downtime, changeover is a planned activity, but it also affects equipment utilization. Its output is changeover time data, typically optimized through SMED methods, with the goal of reducing changeover time to support smaller production batches.
Example in practice
An injection molding factory frequently needed to change molds to produce different products, with each changeover taking 2 hours, forcing large-batch production. To meet customer small-batch orders, they applied the SMED method, converting internal operations to external operations and optimizing adjustment steps, ultimately reducing changeover time to 30 minutes. This enabled flexible production scheduling, reduced finished goods inventory, and met diverse customer needs.