Waste Reduction and Muda, Mura and Muri

Most definitions of lean manufacturing refer to the reduction of the Muda (7 wastes) as the main focus. Few definitions of lean differentiate between the different types of waste and seem to purely focus on Muda. The Toyota Production System (TPS) sees waste as being three — Muda, Mura and Muri — something that many lean practitioners seem to have forgotten. The best way to tackle a problem is to remove the root cause, therefore the focus of any waste reduction program should be on removing both Mura and Muri, as this will automatically remove much of the Muda (7 wastes) in the workplace.

The overall aim of any quality improvement technique is to improve the profitability of the business. To do this you have to be able to recognize these three wastes for what they are and be able to tackle the root causes.

Muda – Commonly referred to as the 7 Wastes and are non-value adding processes or actions.

Mura – Seen as unevenness or a lack of stability and flow. This drives the creation of Muda.

Muri – This is simply defined as overburden. Expecting too much, with defining process or not having the correct skills or tools.

The three Japanese Mu words are part of the Toyota Production System (TPS). Each of these is a type of waste and are recognized by the Japanese as part of a business improvement initiative. The elimination of waste has come to dominate the thinking of many when they look at the effects of the TPS because it is the most familiar of the three to implement. In the TPS, many initiatives are triggered by inconsistency or over-run reduction, which drives out waste without specific focus on its reduction.

In today’s competitive environment, a focus on reduction of waste is crucial to the success and profitability of any organization. Eliminating waste makes it easier to see and find problems, which is the first step to solving them. It removes frustrations, which improves worker and customer satisfaction.