Talichi Ohno developed a system for Toyota that focused on the continuous improvement of quality and the elimination of waste. The types of waste as defined by Ohno fell into three distinct categories, which are muri, muda, and mura.

Overview: What is muri?

Muri is a Japanese word that can be defined as unreasonableness or going beyond one’s power. It is used to describe one of the three categories of waste as described by Talichi Ohno, the type of waste that comes from processes that are overtaxing or overly complicated. Some examples would be expecting an employee to perform at an optimum level after eight hours or expecting a machine to do more than it is capable of in a given amount of time.

3 drawbacks of muri

There are some major drawbacks to having muri present in your workplace that are worth noting:

1. Employee absenteeism

Too much muri can lead employees to become absent from work more regularly, due to fatigue.

2. Illness

Muri can also lead to employees falling ill, due to them being overburdened for too long and their bodies becoming weaker and more susceptible to illness.

3. Machine breakdown

Muri can also cause a breakdown of machines from them working to produce over their capacity.

Why is muri important to understand?

Muri is important to understand for some key reasons:

Optimizing production

Work processes are dynamic, so some waste is likely unavoidable. Therefore, it is important to understand the three types of waste so that the optimum balance can be found that is best for production.

Many focus on muda and mura, forgetting muri

It is important to understand muri because many often make the mistake of focusing on mura and the seven wastes of muda. Eliminating as much muri as possible is critical for a smooth workflow.

Morale

Understanding muri and why it should be eliminated is important because it can have a significant effect on the morale of your team.

An industry example of muri

A manufacturing plant has a tight deadline for the holidays. Instead of hiring seasonal workers, the managers are opting to have their employees work longer shifts. Instead of their normal eight hour days, the employees will be expected to work 12 hours. Some workers will be expected to work split shifts of two eight hour shifts in a day, with a significant break between the two shifts.

Some management are voicing criticism at this plan, as it is believed that overworking the employees will create a significant amount of muri. It is expected that the quality of the work will suffer.

7 best practices when thinking about muri

If you are looking to have less muri in your workplace, here are some key practices to think about:

1. Keep deadlines realistic

One way to prevent muri from affecting your workplace is to set realistic deadlines for your team. Rushing work beyond the capacity of your workers will likely result in substandard products and unhappy customers.

2. Improper training

One thing to think about is making sure that your team members have the proper training when moving into a different position. Too often, workers are pulled from one area that they have a lot of experience in and are placed in another where they have little to no experience. This requires time for an employee to learn by doing, likely not being able to keep the pace that is desired.

3. Maintain good communication

In order to prevent overburdening, it is important for you to keep clear and open communication channels with your staff. This can be helpful in preventing overburdening by everyone knowing what is expected of them at the same time.

4. Have the proper tools

Not having the right tools available for a project inevitably leads to muri, as workers will have to work way harder while achieving less-than-desirable results.

5. Map workflow

One way to help prevent muri is by having the workflow for all processes in a project mapped out. This keeps there from being less guesswork, less downtime, and less muri waste.

6. Standardization

Having workflow standardized and staff well-trained and familiar helps prevent muri.

7. Jidoka

One helpful practice in preventing muri is by embracing the concept of jidoka. This means allowing any worker to stop processes whenever problems happen.

Frequently Asked Questions (FAQ) about muri

What are the other two main categories of waste?

Other than muri, there are muda and mura. Mura means irregularity or unevenness and is thought of as the reason for the existence of any of the 7 wastes listed in muda. Mura typically occurs when standards of production are less than ideal.

Muda lists 7 classic types of waste. These are transportation (i.e., products being moved around too much), inventory (i.e., poor stock-keeping), movement (i.e.,  people being forced to move too much), waiting, overproduction, overprocessing, and defects in product. These wastes are symbolized by the acronym TIMWOOD.

How do the other two wastes relate to muri?

Too much of either or both of the other two kinds of waste can contribute to excessive muri.

How are the three wastes simplified in terminology?

You will often see muri, muna, and mura listed as 3M.

Finding a balance with the three categories of waste

Muri, muda, and mura all relate to one another, and it is extremely difficult to eliminate all waste from the categories. What is important in business is to do all that one can to eliminate as much waste as possible from these three categories, knowing that any changes made to one category of waste will likely have an effect on the others.