Lean distinguishes three types of variations. Elimination of variation and waste is an important starting point within Lean.

● Muda (Waste, uselessness, non-value-added, not suddenly good)
● Muri (Overload, impossibilities, beyond someone’s power or expertise)
● Mura (Irregularities, irregularity or lack of uniformity)

In most Lean programs, Muda is the first M to be picked up, because it is easier to identify than the other two. Reducing Muda can be achieved by eliminating activities that do not add value. Each activity in a process can be classified as:

● Value Adding (VA); Customer is willing to pay for this.
● Non-Value Adding (NVA); Customer is not willing to pay for this.
● Necessary for the process.

reducing waste

A Value Adding activity needs to meet the following requirements: the customer is willing to pay for the activity, it must be executed correctly for the first time (First Time Right) and the action must change the product or service in a certain way. If one of these criteria is not met, the activity is classified as a Non-Value Adding and thus as waste or ‘Muda’.