Muda, Mura, Muri – The Toyota 3M Model | Industrial Trainer

3M Principle

Muda, mura, and muri are Japanese terms that refer to the three categories of waste found in a business. Understanding each is key to implementing proper lean manufacturing processes.

What is 3M

3M stands for Muda Mura Muri (斑,) which is a Japanese word. These are used by Toyota Production System (TPS) to identify and eliminate different types of waste in its system.

The Toyota 3M model, also known as the “Muda, Mura, Muri” model, is a continuous improvement framework used by Toyota Motor Corporation to improve the efficiency and quality of their manufacturing processes. The three “M’s” in the framework represent the following concepts:

1. Muda: This refers to waste, and specifically refers to activities or processes that add no value to the product or service being provided. In a manufacturing context, it can refer to things like excess inventory, redundant steps in a process, or defects that need to be reworked.
2. Mura: This refers to unevenness or inconsistency in a process. For example, if production output fluctuates greatly from one day to the next, that would be considered mura.
3. Muri: This refers to overburden or strain on a process or system. If a machine is constantly pushed to its limits, for example, that could be considered muri.

Identifying and Eliminating Waste is the main objective of Lean Manufacturing and Kaizen, but today we will learn to Identify and Eliminate Waste with the help of 3M here.

Muda (WASTE)

Muda is a Japanese term that refers to waste or inefficiency in a process or system. In the context of continuous improvement and Lean manufacturing, muda is any activity or step in a process that adds no value to the end product or service. This can include things like excess inventory, redundant steps in a process, defects that need to be reworked, or anything else that does not contribute directly to the customer’s satisfaction.

The goal of reducing muda is to streamline processes and make them more efficient, which can lead to improved productivity, lower costs, and higher quality products and services. By continually identifying and eliminating muda, organizations can improve their processes, increase the overall efficiency of their operations, and provide better value to their customers.

What is Muda?

In an organization or factory, 95% of the activity is wasted, and only 05% of the activity gives value to the factory. This means that there are two types of activity:-

1. Value Added Activity (VAA)
2. Non-Value Added Activity (NVAA)
3. Necessary Non-Value Activity (NNVA) (Type 1)
4. Pure Waste (Type 2) or Muda

There are seven types of muda (waste) in Lean manufacturing, as identified by Taiichi Ohno, the father of the Toyota Production System:

1. Overproduction: Producing more than what is needed, leading to inventory buildup and increased costs.
2. Waiting: Employees waiting for materials, equipment, or information to arrive, leading to idle time and reduced efficiency.
3. Transport: Unnecessary movement of materials, people, or products, leading to increased costs and decreased efficiency.
4. Processing: Unnecessary steps in a process, such as rework or excess inspection, leading to increased costs and decreased efficiency.
5. Motion: Unnecessary movement by employees, leading to increased fatigue and reduced efficiency.
6. Inventory: Excessive inventory levels, leading to increased storage costs and decreased efficiency.
7. Defects: Rejected or defective products, leading to increased costs and decreased efficiency.

People Wate:-1.Over Processing, 2. Motion, 3. Waiting

Quantity Waste:-1.Transportation, 2. Over Production, 3. Inventory

Quality Waste:-1.Defects

Mura (UNEVEN)

Mura is a Japanese term that refers to unevenness or inconsistency in a process or system. In the context of continuous improvement and Lean manufacturing, mura can refer to fluctuations or irregularities in production output, quality, or delivery times, among other things. Mura can lead to increased costs and decreased efficiency, as well as decreased customer satisfaction.

Examples of mura include:

1. Fluctuations in production output, leading to inefficiencies and increased costs.
2. Irregularities in quality, leading to rework, scrap, and decreased customer satisfaction.
3. Uneven delivery times, leading to increased costs and decreased customer satisfaction.
4. Inconsistent staffing levels, leading to increased costs and decreased efficiency.
5. Unpredictable machine downtime, leading to increased costs and decreased efficiency.

The goal of reducing mura is to create a smoother, more consistent production process, which can lead to increased efficiency, lower costs, and higher quality products and services. By identifying and addressing the sources of mura in their processes, organizations can improve their operations and provide better value to their customers.

What is Mura?

Mura means Unevenness, Irregularity, or Inconsistent as the name suggests that there is no standard time in the process.

When there is no standard time for our process, when the part is made early by some process, and sometimes the part is made late by the same process. Such a process is called Unevenness, Irregularity Inconsistent Process, or Waste.

To reduce this type of waste, while designing the process, it should be kept in mind that the cycle time of the process should be standard. To reduce this waste, we should study the cycle time of all the processes in the line and do line balance so that our product continues to flow and the cycle time of all the processes is the same every time.

When we reduce the Unevenness, Irregularity, or Inconsistent type of Waste from the process then it is called Mura.

Useful Links:

• Productivity Tools
• Quality Tools
• Process optimization Tools
• Lean Manufacturing Tools
• How to Apply for MNC Jobs

Muri (OVERBURDEN)

Muri is a Japanese term that refers to overburden or strain on a process or system. In the context of continuous improvement and Lean manufacturing, muri refers to activities or processes that push people, machines, or systems beyond their limits. This can result in increased costs, decreased efficiency, and decreased customer satisfaction.

Examples of muri include:

1. Overloading machines, leading to increased downtime and decreased efficiency.
2. Overburdening employees, leading to increased fatigue and decreased efficiency.
3. Overloading suppliers, leading to decreased delivery times and decreased customer satisfaction.
4. Unmanageable workloads, leading to increased stress and decreased efficiency.

The goal of reducing muri is to create a more sustainable production process, which can lead to increased efficiency, lower costs, and higher quality products and services. By identifying and addressing the sources of muri in their processes, organizations can improve their operations and provide better value to their customers.

What is Muri?

Muri means Unreasonable or Overburdening. When more work is done than any worker or machine, it is called Overburdening type of Waste.

When we run a machine more than its capacity, then break-down starts coming in it due to which the flow of the line gets disturbed and the product is not ready on time which is a huge waste.

Similarly, when there is a process in the line where one worker is overloaded or has to do more work, he will get upset and will not work on the second day, which will disturb the balance of the line and increase the cycle time of the process. It is a type of waste.

When there is a process in the line where workers face difficulty in working and not everyone wants to work there and the workload falls on some operator, then efforts should be made to simplify such operation.

Apart from this, we should distribute less so that there is no overload or load on any one worker or machine and we should keep the line balance and cycle time of all the processes should be same every time. So that there is no overburden on any one worker or machine and the waste should be controlled. Waste caused by overburdening is called Muri.

Also Read:-

• 3G Gemba, Gembutsu, Genjitsu
• 3K 3M 3R 4M
• 4M Analysis
• Learn HMI and SCADA

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