Featured Video
This Week in Quality Digest Live
Lean Features
Jeff Dewar
We’re equipped with a data input tool of enormous bandwidth
Gwendolyn Galsworth
Visual information sharing is the platform on which lean happens
Bob Emiliani
Pondering a decades-long confusion
William A. Levinson
Get ahead of ISO 9004:2018 by turning your company’s culture and identity into a competitive advantage
Tonianne DeMaria Barry
Five ways our brain can thwart lean and how to mitigate them

More Features

Lean News
Ask questions, exchange ideas and best practices, share product tips, discuss challenges in quality improvement initiatives
It’s time that healthcare began to learn a long-term strategic approach to transformation
Combines 3D scanner, touch probe, and software to reduce production times by 30%
Phillips Precision rounds out Inspection Arsenal quick-swap fixturing with Loc-N-Load plates
Partnership for a Cleaner Environment (PACE) program has grown to more than 40 suppliers in 40 countries
Describes how the company applied lean tools and techniques across its products, processes, and partners
Learn the genba kaizen method by which all other kaizen is compared

More News

Joel Bradbury

Lean

Muda, Mura, Muri

You can’t eliminate waste unless you also deal with two other process concerns

Published: Wednesday, March 8, 2017 - 13:02

One of the most important goals of lean manufacturing is the elimination of waste. Taiichi Ohno, father of the Toyota Production System (TPS), defined three categories of waste: mura, muri, and muda. While muda is the most widely known, muri and mura are equally important to understand.

Muda

Muda refers to processes or activities that don’t add value. These types of waste do not help your business or workers in any way. They increase costs and make tasks take much longer than they should. Wastes are defined in TPS as follows:
Overproduction occurs when items are manufactured before they are required.
Overprocessing occurs when more work is put into a product or service than is actually required.
Inventory is important, but storing too many or too few supplies and finished goods increases costs and can take valuable space.
Transportation is the movement of products and supplies from one area to another.
Motion is the physical movement of a person or machine required to complete work.
Waiting is when work or projects come to a halt or slow because machines have yet to finish producing the required goods, products have not arrived, or some other task is holding up the rest of the project.
Defects occur when errors and rework are created because of your processes.

Finding and eliminating muda is essential if you want to reduce costs, improve efficiency, and increase profits. However, if you don’t also address mura and muri, these benefits will be inconsistent or may even fade over time.

Mura

Mura is a type of waste caused by unevenness in production and services. It is also caused when standards are nonexistent or are not followed. One common example is when companies ramp up production to meet targets, even when there is no customer demand. This forces the sales department to rush to try to fill orders and creates a burden as the shipping department rushes to ship products before the end of the month.

The result? Defects are manufactured into products. Customers receive inconsistent products or services. The production floor struggles to complete large orders and becomes idle as orders slow. Even more concerning is that mura creates muri (overburden), which in turn undermines efforts to eliminate the seven wastes of muda.

Muri

The third category of waste is the result of tasks or processes that are overly difficult, or ones that overburden workers. For the most part, this is caused when workers:
• Lack proper training
• Have no standards to follow
• Are given the wrong tools for the job

When workers lack the right tools for the job, for example, tasks become much more difficult, taking more time and potentially damaging the product. For instance, working sheet metal with the wrong hammer and dolly will damage the panel you are working on—tripling the time it takes to complete the task and requiring products to be reworked.

In the same manner, using your email inbox to manage the tasks you must complete makes the tasks more difficult than they should be. Keeping emails to remind you of tasks to complete causes hundreds, if not thousands of emails to accumulate. As a result, it takes too long to find important information and may cause you to overlook important information, potentially causing projects to fall behind schedule or causing others to stop their work as they wait for a response.

Eliminating muda, mura, and muri

Use 5S floor marking and labels to organize the workplace.
Here, floor marking helps keep the area organized, and the shadow board helps workers quickly identify where tools belong.

The purpose of lean manufacturing is to find and eliminate muda, mura, and muri, in order to improve quality, safety, and efficiency. One lean tool that can help you eliminate these forms of waste is the 5S system. 5S helps to declutter, clean, and organize the workplace using the five “S” principles: sort, set in order, shine, standardize, and sustain.

Sort is the first step in 5S. During this phase, you remove tools, supplies, and equipment that are not part of the work process. This declutters the workplace, freeing up space that was previously ill-used.

Set in order is the next step, requiring you to organize the workplace and everything in it to improve the flow of work, based on how work is actually done.

Shine, the third step, requires you to clean the workplace and restore everything to its original condition. This makes it easier to spot equipment and product defects that may have otherwise been hidden.

Standardize, the fourth step, requires you to develop rules that will ensure work is completed consistently and that 5S is applied uniformly and regularly.

Sustain is the final step of 5S. It requires that you work to ensure that 5S becomes a daily habit.

5S and lean resources

The 5S system provides a systematic method for improving your workplace. Learn more about how 5S can improve your workplace with the comprehensive Best Practice Guide to the 5S System, ensuring you have the tools and training needed to make 5S successful.

Graphic Products’ full line of visual communication tools can support your 5S program. DuraLabel industrial label and sign printers and supplies enable you to print labels to identify tools, equipment, and supplies. Meanwhile, custom, color-coded labels will help workers identify categories of tools, supplies, and more.

Streamline your workplace with PathFinder floor-marking tapes. Ensure everything has a place by outlining spaces for workstations, supplies, and so forth. Create lanes for powered vehicles and workers, improving safety and helping work flow efficiently.

Discuss

About The Author

Joel Bradbury’s picture

Joel Bradbury

Joel Bradbury specializes in writing detailed resources such as articles and best practice guides on lean, 5S, kaizen, OSHA compliance, and organizational safety topics at Graphics Products, provider of visual and safety supplies in Beaverton, Oregon. Prior to this Bradbury wrote tech manuals, spec guides and brochures, and other technical material for the mining industry. Bradbury has a master’s degree in rhetoric and technical communications.

Comments

Muda or Mura?

"While muda is the most widely known, muri and muda are equally important to understand."

I beleive the second reference to muda should be mura. I think there is a type. 

Thank you, Dirk

mura it is

Good eye. We made the change. Thanks.