Waste – The 7 types of muda

Muda, the Japanese term for waste, is a central concept in lean production. It stands for everything that does not create value and should therefore be avoided in terms of economic thinking.

Overproduction is the production of services that are not in demand or that exceed demand. It is often referred to as the “mother of all wastes” as many other forms of waste result from it. Overproduction can hide inefficiencies as its symptoms are often not obvious.

Transportation is another form of waste (see also material flow analysis). They should be avoided as far as possible, as they cost time and are an indicator that the material flow is not optimized. If a product has to be transported, this is a sign that the process is not “lean”.

Waiting times are another form of waste. They occur when work steps are not perfectly coordinated. Waiting times are periods in which productivity is zero and should therefore be minimized.

Errors and repairs are another form of waste. A central approach of lean production is error prevention. By focusing on processes, sources of errors can be identified and eliminated at an early stage, making subsequent repairs superfluous.

Travel times are times in which only distances have to be covered and productivity is therefore zero again. They should be kept to a minimum.

Inventories are a major form of waste (see also inventory management). They take up space, tie up capital and should therefore be kept to a minimum. Ideally, they should be eliminated without compromising customer benefits, as a certain degree of flexibility must be retained.

Space is one of the seven types of waste (see also dimensioning). Only the capacities that are really needed should be used. Too much space leads to long transportation routes, high space costs and inefficient material flow and therefore falls under the concept of waste.

Overall, the aim is to minimize or eliminate these seven types of waste in order to increase efficiency and productivity.