7 Wastes or the Toyota Seven Forms of Muda

One of the key steps in Lean and TPS is the identification of which steps add value and which do not. By classifying all the process activities into these two categories it is then possible to start actions for improving the former and eliminating the latter. Some of these definitions may seem rather ‘idealist’ but this tough definition is seen as important to the effectiveness of this key step. Once value-adding work has been separated from waste then waste can be subdivided into ‘needs to be done but non-value adding’ waste and pure waste. The clear identification of ‘non-value adding work’, as distinct from waste or work, is critical to identifying the assumptions and beliefs behind the current work process and to challenging them in due course.

The expression “Learning to see” comes from an ever developing ability to see waste where it was not perceived before. Many have sought to develop this ability by ‘trips to Japan’ to visit Toyota to see the difference between their operation and one that has been under continuous improvement for thirty years under the TPS. Shigeo Shingo, a co-developer of TPS, observed that it’s only the last turn of a bolt that tightens it – the rest is just movement. This level of refined ‘seeing’ of waste has enabled him to cut car body die changeover time to less than 3% of its duration in the 1950s as of 2010. Note that this period has allowed all the supporting services to adapt to this new capability and for the changeover time to undergo multiple improvements. These multiple improvements were in new technologies, refining value required by ‘downstream’ processes and by internal process redesigns.

The following articles explain the Toyota “seven wastes” by example, showing how the 7 forms of Muda can be identified in any context.

Credit goes to Taiichi Ohno, for he identified common resources that either produce waste or were a impacted by waste. They were identified by Toyota’s Chief Engineer, Taiichi Ohno as part of the Toyota Production System