Lean manufacturing is a management philosophy. This philosophy was basically derived from the Toyota Production System. The main focus of this system is to get rid of wastes in the production process referred to as Muda. The good thing about this philosophy is that it takes into consideration different types of waste that encompasses waste of high level of human motion. By eliminating waste, this system aims at bringing together every step of production into an efficient and holistic process that improves overall revenues and brings down the cost. When it aims at eliminating waste, still 7 wastes of lean are common in lean manufacturing. We are here to throw some light on these wastes of Lean Production:

Know About Muda, Mura and Muri:

Getting rid of wasteful activities is one of the most crucial requirements when it comes to building a successful organization. In Lean thinking, this concept is crucial and by paying attention to eliminating waste, Lean aids in improving productivity in any organization. 

As mentioned earlier, the idea of waste elimination originated from the Toyota Production System. One of the founding fathers of Lean Manufacturing Taiichi Ohno dedicated his entire career to establishing an efficient and solid work process. In this journey, Ohno explained three crucial hindrances that can come in the way of an organization’s work in progress negatively. These blocks are explained by him as Muda, Muri and Mura. The first of these denotes wasteful activities, the second denotes overburden and the third is unevenness. On the basis of his findings after deep analysis, Ohno categorized seven waste of lean otherwise called 7 mudas. It later turned out to be a familiar practice for resource optimization and cost reduction.

Meaning of Muda or Lean Waste:

In Lean, waste denotes any activity that consumes resources. Even though resource consumption happens, it does not bring any value to the end-user. However, of the entire work in progress in an organization, only a small percentage can bring value to consumers. This is why organizations are recommended to pay attention to bringing down wasteful activities as much as possible. When they do this, organizations will be in a position to identify considerable opportunities for improving their performance as a whole. However, the thing to remember here is that it is not possible to get rid of all wasteful activities from the work in progress. The reason is that some wastes are necessary. For instance, software testing in a software development company is not an activity that customers pay for. Nevertheless, without testing the software, it might not be possible for the software development company to deliver the best-quality software. So, you can categorize the wastes into two main categories. They are necessary wastes and pure wastes.

• Necessary wastes do not add any value. But, they are essential to get things done qualitatively. Examples of these activities can be reporting, planning and testing.
• Pure wastes also do not add any value but they are different from necessary wastes because they are not necessary. These wastes include activities that do not bring any value and can be removed from the process with immediate effect. You can describe any form of waiting, otherwise known as waiting waste as pure waste.

Meaning of Mura:

Mura denotes the waste of inconsistency and unevenness in Lean Six Sigma. It can have more than a single manifestation based on the nature of your business. A pre-requirement for unevenness is the inefficiency to straighten your process and create a balance in activities. As an outcome, your team will put its efforts into the process as quickly as possible. They will start producing one big batch over the other without any thought or with a little thought of how the process will withhold the burden. 

Meaning of Muri:

Muri will occur when you put your team under a lot of stress by demanding unnecessary and unreasonable work that is far more than their capacity. You can very well understand that Muri can bring down not only the efficiency but also the productivity of your team due to overburden. When you put a lot of pressure on them, your team members will have to extend their working hours. In turn, it can contribute to occupational burnout. Overburdening can affect the morale of your team a lot. It can even damage the entire healthy production process. 

It is like giving a lot of work to three members of your team just because they are performing well. When you do this, they can get sick. When this happens, the entire process will be affected. The idea here is to balance at the optimal capacity. It is the level at which every portion of the system can deliver outcomes without requiring additional work.

Muri takes place when one resource is overburdened with a lot of tasks, while the other waits at the same time. Otherwise, it is where under-utilization of some resources and over-utilization of some resources take place, thereby creating overburden on the latter happens. When this happens, your processes will turn out to be less predictable and your team will start struggling to deliver value at a steady pace.

Now, you know about Mura, Muri and Muda. Of these three, the 7 wastes of lean management come under Muda. Here are the details about these 7 wastes.

7 Muda or Wastes in Lean Sigma:

1. Transport:

Among seven types of waste lean, transportation waste is also one of them. Waste in transportation encompasses the movement of products, equipment, inventory, tools and people. Of course, transportation becomes essential. But, the waste includes transportation that happens more than the required limit. The reason is that excessive movement of raw materials can contribute to product defects and damage. When people move more often, it can lead to exhaustion. When raw materials move a lot, there are chances of greater wear and tear. In the same way, excessive movement of both people and materials can lead to unwanted work. When you take the case of a factory, raw materials required for the production should be accessible with ease to workers. Here, triple or double handling of materials should be avoided. Some of the countermeasures to waste of transportation encompass the development of a U-shaped production line. In turn, it will create a flow between processes. It will help with the avoidance of overproduction of items in work-in-process.

2. Inventory:

Many items in the Work-in-process result from overproduction and waiting. It will contribute to the excess stock of produced goods on the plant floor. When products wait in the inventory for long, manufacturing units will have to spend a lot. The reason is that management needs resources to manage those items in the inventory. Also, the space occupied by the inventory can be used for storing raw materials required for the next production cycle when sudden orders come up.

3. Motion:

When talking about the seven waste of lean, not only transportation but also the motion of people and machines from one place to another is considered a waste. Here, motion can denote anything from a worker bending down to picking up a raw material required for the production. It is believed that unnecessary motion can lead to extended time to produce, injuries, etc. In other words, to prevent this waste, you will have to do whatever is required for arranging a process such that employees need not have to do many movements to finish their work.

4. Waiting:

Waiting denotes the waiting that a person or machinery will have to do to complete a task. This waiting is common to happen when one process in the production takes longer to complete than the time expected for the completion. When this happens, there will be a waste of production time. When waiting for production, materials can be spoiled, while workers should be paid even for the waiting time. In turn, the cost to the company will increase.

5. Overproduction:

If you are in the manufacturing field for a long time, you very well know that overproduction is the most obvious form of waste. Apart from contributing to depleted raw materials, it can also contribute to wasted storage and more funds locked up in unused products. 

If your team consistently produces more, based on the nature of your product, you might be forced to dispose of some products. There are chances that you can create environmental damage when you do this. Disposal also leads to a waste of human effort. Even, there are chances of risk of exposing your workforce to harmful waste materials.

Your team and even your organization as a whole should aim at producing only what customers need. Lean Manufacturing depends on a 'just-in-time' policy. It means that a product should be produced only at the time it is required and not early.

6. Over Processing:

Not only over-production but also over-processing is one of the 7 wastes of lean management. It means doing more work and adding more components or having more steps in the service or product as compared to what is actually needed by customers. For instance, the usage of higher precision equipment than what is required denotes over-processing. Also, using components with capabilities more than what is required is over-processing. 

7. Defects:

One of the confirmed among the 7 wastes of lean is defects in the product. But, the problem with this waste is that it remains unnoticed until the products reach customers. Errors in quality that lead to defects can cost you far more than your expectation. When an item is defective, it needs replacement or reworks. In turn, both materials and resources become waste. It can lead to customer dissatisfaction and even a lot of paperwork. So, preventive actions should be taken to avoid defects. For instance, automation and poka-yoke systems can help with defect prevention.

Conclusion:

The seven types of waste lean are shortly referred to as TIMWOOD. You can relate each letter in this term to the appropriate wastes above. Even, for easy memory, the 7 together are otherwise called WORMPIT, which means waiting, overproduction, rejects, motion, processing, inventory and transport.