Sustainability in Business

Waste in the workplace: Muri, Mura and Muda

Today I would like to discuss something that affects most businesses, especially production facilities (although we see this in other industries as well). It is how we tend to waste without even realizing it in most cases. 

I am using information and examples from a blog that posted in August, 2017, by the Lean Way Blog, published by Doanh Do. The information pertains to lean manufacturing, a way to optimize production. It was mostly developed by Toyota in Japan.

There are normally three situations in the workplace that are undesirable. They are:

• Muda: the Japanese word for wastefulness, uselessness or futility
• Mura: the Japanese word for unevenness, non-uniformity or irregularity
• Muri: the Japanese word for over-burden, beyond one's power, execiveness, impossible or unreasonableness

I would like us to look at each in a bit more detail:

Muda

Muda is anything that does not add value to the process. Value added work is a process that adds value to the product or the service, and that the customer is willing to pay for. Anything else is Muda, or waste. 

We get 2 types of Muda in the workplace. 

Type 1 Muda includes the non-value-adding activities in the process. These activities are necessary for the end-customer, but they do not add any value in themselves. Inspection and testing does not directly add any value to the final product, but we need to do it to ensure that the customer will receive a quality and safe product. This is the type of Muda that is essential, and we cannot eliminate it completely.

Type 2 Muda  includes non-value-adding activities in the process. These activities are unnecessary for the customer. An example would be excessive cleaning of parts, which does not affect the customer in any way, and the customer would also not be willing to pay for it. Type 2 Muda must be eliminated.

There are, in general, 7 types of Type 2 Muda:

Transport

Transport does not add any value to a product or a service. It is caused by excessive movement of product. It costs money. Examples of excessive transport include:

• Moving inventory in and out of storage
• Moving product from one workstation to another
• Moving product around the storage area (often to re-organize the storage area)
• Etc

Causes include:

• Batch production
• Push production systems
• Storage facilities and problems
• Functional layout in the production area
• Etc

Inventory, stocks of goods and raw materials

This happens when we have more material and other items than what we need now to service our customers. 

Examples include:

• Raw material stocks
• Work-in-process
• Finished goods that is stored (because it is not sold)
• Consumables
• Purchased components
• Etc

Excessive inventory is often caused by:

• Supplier lead times
• Lack of flow in the process
• Long set-up times
• Long lead times (our own)
• Paperwork in the process
• Not placing purchase orders in time
• Etc

Motion

Motion is excessive movement of machinery or people that does not add any value.

Examples of waste through motion are:

• Searching for tools, parts, paperwork, etc
• Sorting through materials
• Reaching for tools that should be within easy reach
• Lifting boxes or parts
• Etc

Waste through motion is often caused by:

• Disorganized workplace
• Missing items
• Poor workstation design
• Unsafe work area
• Etc

Waiting

Waiting includes idle time created when material, information, people or equipment is not ready.

Examples of this category of waste include:

• Waiting for parts
• Waiting for paperwork
• Waiting for inspection
• Waiting for machines
• Waiting for information
• Waiting for machines to be repaired
• Etc

The causes of this type of Muda include:

• Push production
• Work imbalance
• Centralized inspection
• Production order entry delays
• Lack of priority
• Etc

Over-production

Over-production happens when we produce more than what we need right now to service our customers.

Examples of over-production include:

• Producing product for stock based on sales forecasts
• Producing more than we need to avoid costly set-ups
• Batch production resulting in extra output
• Etc

Over-production is often caused by:

• Forecasting
• Long set-up times
• Producing just-in-case of breakdowns
• Etc

Over-processing

Over processing is effort that carries no value form the customer's point of view. The customer is normally not willing to pay for this, because he does not see any value in it.

Examples for over-processing include:

• Multiple cleaning of parts
• Paperwork
• Over-tight tolerances
• awkward tool or part design
• Etc

The causes of over-processing include:

• Push production systems
• Not understanding the customer requirements clearly
• Impractical design where producibility was not considered, and production was not involved in the design process (designs "thrown over the wall")
• Delays in the process
• Etc

Defects

Defect is work that contains errors, rework, mistakes or product lacking something necessary.

Examples of this category of Muda include:

• Scrap
• Rework
• Defects in the product
• Corrections
• Field failures
• Variation between products
• Missing parts
• Etc

Causes of defects include:

• Process failures
• Parts in the wrong place
• Batch processing
• Trying to inspect quality into the product
• Incapable machines or equipment
• Incompetent people
• Etc

Our mission should be to get rid of as Muda as possible in our organizations. It is like a drain sucking up money that we will never see again. When we talk about cost of quality later we will see the devestating effects that Muda and poor quality can have in our businesses.

We get rid of Muda by:

• Making waste visible in the workplace
• Being conscious of waste
• Being accountable for waste
• Measuring waste
• Eliminating or reducing waste

Mura

Mura is translated as unevenness, non-uniformity or irregularity in the workload in a process. Mura is the cause of many of the 7 types of Muda that we have discussed. 

An example of Mura: When, in a manufacturing line, products need to pass through several workstations during assembly, and the capacity of one station is greater than the other stations. There will be an accumulation of waste in the form of over-production, waiting, excessive inventory, etc. We need to level out the workload so that there will be no unevenness or waste accumulation. 

Mura can be eliminated by applying pull-based production strategies that will limit over-production and excessive inventory.

Muri

Muri means overburden, beyond one's power, exessiveness, impossible or unreasonableness. It results from Mura, or uneven, unbalanced production processes. 

It can also be caused by excessive removal of Muda from processes. 

It also exists when machines or operators are utilized more than 100% capability to complete a task, or in an unsustainable way.

Muri can lead to operator absenteeism or illness, and to breakdowns in machinery. Standardized work processes can help to avoid Muri. 

Design the work processes to evenly distribute the workload and not overburden any employee or equipment.

Graphic representation

Graphically, Muda, Mura and Muri can be shown as follows:

Remember that the three are interrelated. Eliminating problems in one can affect the other two. Always look at the risk created when you want to make any changes (Risk-Based-Thinking).

I hope that this is helpful! Feel free to leave a comment, or to contact me at koosgouws10@gmail.com. 

You can visit our website at www.sheqmanagementsystem.co.za.

Koos