We don’t want waste. Not at all! But we need to understand there is waste and waste.

The Toyota Production System, originating the concept of Lean, has identified several types of wastes, three types of deviations that shows inefficient allocation of resources. These three types are Muda (waste), Mura (unevenness), and Muri (overburden).

Muda

Muda effectively means wastefulness. Uselessness and futility, reducing the effective value of a product. There are two types of Muda, Type 1 and Type 2. Muda Type 1 includes non-value-added activities in the processes that are necessary for the end customer. For example, inspection and safety testing does not directly add value to the final product; however, they are necessary activities to ensure quality for customers. Muda Type 2 includes non-value added activities in the processes, but these activities are unnecessary for the customer. As a result, Type 1 should be optimized, while Type 2 should be eliminated.

Mura

Mura means unevenness, non-uniformity, and irregularity. For example, in a manufacturing line, products need to pass through several workstations during the assembly process. When the capacity of one station is greater than the other stations, there is an accumulation of waste in the form of overproduction, waiting, etc. The goal is to level out the workload so that there is no unevenness or waste accumulation.

Muri

Muri means overburden, excessiveness, impossible or unreasonableness. For example, when machines or operators are utilized for more than 100% capability to complete a task or in an unsustainable way. Muri over a period of time can result in employee absenteeism, illness, and breakdowns of machines. Standardize work can help by designing the work processes to evenly distribute the workload and not overburden any particular employee or equipment.

Conclusion

In real world applications, it is not always easy or possible to find an optimal solution. Reducing Muda can lead to Muri. The existence of Mura can be seen as a waste in Muda. And Muri can lead to a breakdown in the system that will result in a large amount of Muda and Mura.

Real world problems are dynamic, and needs of customers are always changing, so work processes must also change as well and be ready to adapt. But, at the sme time, for a safe environment we need to look at the overal system, trying to reduce as much as possible these three kind of wastes, if we don’t want to deal with worse problems.