Muri

Muri is a Japanese term for a specific form of waste. It means unreasonableness or overexertion. It is often referred to with two other Japanese terms. Muda is the traditional view of waste in which resources are used without adding to output. Mura is inconsistency or unevenness, usually as a result of variation in methods or customer demand.

When people and machines are pushed beyond a reasonable limit, they tend to have diminished performance, which leads to increased costs. In the case of machines, muri causes faster wear and tear, quality problems, and catastrophic breakdowns.

For people, muri causes increased stress, fatigue, injuries, and generally reduced job satisfaction. Of course, machines don’t have opinions about what “reasonable limits” are. People, however, do. Part of respect for people entails negotiating a pace that provides strong productivity without burning people out.

There are also performance problems associated with operating close to capacity. Companies have less flexibility, and often have lead time problems as they have fewer available resources to manage spikes in demand or to deal with problems.