What About the 8th Waste?

When learning to implement Lean manufacturing or Lean office principles one of the essentials is to develop a deep understanding of the 7 types of waste. Many people start working with the tools right away, value stream mapping or doing 5S activity without clearly linking this activity to waste reduction.

The concept of waste (Muda in Japanese) is common sense once it is explained to most people in a Lean manufacturing context. Yet because it is such a simple and universally acceptable idea, some people think it’s too simple and needs to be “improved”. This results in the addition of new wastes, anywhere from 1 to 13 new wastes in our experience.

The main reason we recommend staying with the original 7 wastes is to keep it simple. Other types of waste can almost always be included in one of the 7 types, or they are a cause of the waste rather than a waste itself. For example “complexity” is sometimes included as a waste, but this is more a cause of other types of waste such as transportation or processing waste or the waste of defects that result from complexity.

In the early days of developing the Toyota Production System some 50 years ago Taiichi Ohno identified the original 7 types of waste. He is said to have used the Japanese expression “Even the best person has 7 bad habits” as an inspiration. One question I ask is “If after more than 50 years of waste elimination Toyota hasn’t added new wastes, do you really need to?” While that might stump some people, it doesn’t really help them explain to others why there are 7 and not 8 wastes.

The question we hear the most is “What about the 8th waste, the waste of peoples’ unused creativity?” Some texts on Lean have added this 8th waste. The so-called 8th waste usually describes the fact that the creativity or ideas of the people are not being used to improve the work. While this is clearly a loss that Lean and Kaizen must correct, it is does not fit with one of the 7 types of waste that you can see in a production of service process.

If people’s ideas are not being utilized, this means that you will have more of the 7 wastes (defects, motion, inventory, transportation, overproduction, processing, waiting). It’s important to understand that certain things (like underutilized creativity) cause waste, and waste causes losses in profitability.

In other words:
Unused creativity > less effective processes > 7 wastes > lower profitability

There is an important cause and effect relationship that needs to be understood. Lean implementation is much more about changing behaviors and how people think about work than about actually changing ‘things’ (procedures, factory layout, systems, etc.). The 7 wastes are the link between the root causes (human behaviors) and the loss of profit. Thinking deeply about the 7 wastes and learning to see and measure them in every process is the key to taking quick, effective kaizen action.

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