Definition
Japanese "unreasonable, forced, overloaded".
In detail
Muri (overburden) refers to equipment or people bearing loads beyond reasonable limits, such as excessive overtime or equipment running at excessive speeds, leading to decreased efficiency, quality issues, and safety incidents. In the lean system, Muri is one of the three types of waste, alongside Muda (waste) and Mura (unevenness); eliminating Muri is important for improving the work environment and ensuring employee health. Unlike Muda (non-value-added) and Mura (variability), Muri focuses on overload conditions. Outputs typically include load analysis, job redesign, and equipment maintenance plans.
Example in practice
An assembly line, to meet orders, required employees to work continuous overtime, leading to fatigue and increased error rates. Through employee load chart analysis, they found some workstations' operation times far exceeded takt time, causing overload. They rebalanced work allocation, added auxiliary personnel, and optimized equipment parameters. After improvement, employee loads were reasonable, error rates decreased, and production efficiency actually increased.