TPS Jargon Check: What is the Meaning of Yosedome?

A few months ago Bruno asked, “What is the meaning of yosedome?” Pronounced “yo se dough may” it almost sounds Spanish but it was not a word I had ever heard before and was unable to help Bruno. This week Ian from Toyota was kind enough to provide an explanation:

Yosedome is basically the consolidation of operations or processes to more closely match actual demand. In Toyota, we use it as a principle to reduce cost during periods of low volume or when customer demand is less than capacity. It literally means ‘stopping of processes to match demand’.
A couple of examples :- In our casting plant we have 6 casting machines which gives us a minimum cycle time of 50 seconds. If volume decreases we will only run 5 or 4 or 3 machines to more closely match demand – we’ll stop the other machines.

Another example would be to modify an assembly line to take multiple model types so that we could run the reduced volume down one line as opposed to running two. Yosedome is closely linked to energy reduction activity – the concept of stopping processes that are not needed.

Based on that description I dug a little deeper and found the origin and current use of the Japanese phrase yosedome. Yosedome at Toyota and Japanese companies are a 5 step activity to consolidate underutilized or under-performing assets. The five steps are:

1) 上げる、2) 寄せる、3) 止める、4) 活す、5) 捨てる

In English these are 1) to raise the rate of operation (ageru), 2) to bring equipment closer together (yoseru), 3) to stop utilizing equipment assets with low demand (tomeru), 4) to make good use of the capacity of the equipment that was brought together (ikasu), and 5) to discard unnecessary equipment (suteru). Note that the words in step 2 (yose) and step 3 (tome) combined make up 寄せ止め or “yosedome”. This sort of shortening of phrases into 3 or 4-syllable words as common in Japanese as TLAs (three-letter acronyms) are in English. Karaoke and pokemon are good examples.

Although the energy saving and equipment management aspects of yosedome have been around for many years, the past 18 months has seen some revolutionary change (kaikaku) activities of yosedome as production volumes in the automotive industries have plummeted and Toyota and their suppliers have been forced to “to raise the up time, bring machines close together, to stop running low-utilization machines and even discard redundant equipment while effectively utilizing the remaining equipment. The combination of up time improvement activities with consolidation equipment has a strong positive effect on both fixed and variable costs.

Although it is part of the current TPS vocabulary in that yosedome activities are ongoing as companies consolidate their fixed assets, I wouldn’t recommend adding yosedome to the lean glossary. Its component activities are all useful, but the need itself for yosedome is rather sad. Hopefully as the global economy continues to improve and the need for yosedome lessens this word will find its own small place in the footnotes of the history of lean manufacturing.