What is SMED ?


The question what is SMED is fairly easy to answer. SMED stands for Single Minute Exchange of Dies. In reality the concept has gone beyond just exchanging dies quickly to cover the wider topic of Quick Changeover in general. It should be noted that Single Minute does not refer to 1 minute or less, it in fact refers to anything less than 10 minutes or in other words a single minute digit in the total time.

Shingeo released that if Japanese businesses were to compete they had to be able to change production over far faster than other western businesses. In Post war Japan, there was a lack of capital required to use dedicated production equipment such as North America often did. Additionally the lack of capital also restricted the levels of inventory a business could afford. In that backdrop Shingeo worked to find ways to changeover equipment in less time.

Early on to achieve the goals of SMED or Quick Changeover, it was realized that two distinct sets of operations had to be improved. First engineers, trades people, and equipment designers had to find ways to eliminate internal changes to equipment, by modifying them to make the internal change external or to modify it so no internal adjustments are required any more. Second part this group need to address was with the external changes. They had to tackle several issues, first find ways to short the time required to attach or detach dies, fixtures, and tooling. Additionally they now plan for the changeover in that everything they need to complete the changeover is ready and in place just before it will be required. The last part involves finding ways to modify everything so that if possible the moment it is finished being installed that it is adjusted and ready to operate.

He goal of all these modifications is to short the time from the last good part x being produced to the first good part y being produced. The short this time frame the lower the level of inventory you can hold, and the greater your production flexibility becomes. Together they allow you to produce closer to actual customer demand.