7 types of waste in Lean Manufacturing

For many companies, eliminating waste (also known as muda) can be quite a challenge. Managers often overlook process losses. Large production batches, long changeover times, continuous shortages, non-conforming products, quality problems. These losess in many companies are still no surprise, and are even accepted and treated as a normal way of organizing production.

At the same time, companies that have begun their lean journey and are looking for ways to eliminate waste are beginning to produce more, their production costs are much lower, and their processes and employees are more efficient. This results in increasing their attractiveness in the eyes of customers. What does this “transformation” consist of? All they do is continuously and consistently identify waste in production and logistics processes and effectively eliminate it. To understand what waste is, one must first define the concept of value added.

Value-added simply put, is the operations that the customer is willing to pay for. These will include operations such as cutting, joining, grinding, hardening, welding, painting, assembling, filling and programming a particular piece of equipment. Anything the customer doesn’t want to pay for is wasteful and an additional cost to the business.

7 types of waste

Taiichi Ohno – creator of the Toyota Production System (TPS), supporter of direct process observation, identified 7 types of waste. They are:

1. Overproduction – this is the worst of the wastes. It is the opposite of Just in Time production, which you can learn more about here. Overproduction means producing unnecessary products, at the wrong time and in the wrong quantity. It occurs when we produce goods for which there is no demand. That is, when we produce something for stock, that no one has ordered yet. It is worth noting that overproduction is a source of other types of waste as well, such as excess inventory, shortages, extra transportation, or blocking the flow of materials.
2. Inventory – this may include materials, raw materials, tools, spare parts, documentation. Stocks arise from overproduction, incorrect process layout on the production floor, long changeover times or inadequate production planning.
3. Transportation – is any movement of materials, semi-finished goods, finished goods, tools and parts from one place to another for any reason. The longer the route to travel, the greater the loss.
4. Defects – this is waste associated not only with defective products, but also with the work of quality control department, handling the complaint process, for which the customer does not want to pay us. The causes of shortages are most often related to final inspection, maintained at the end of the line, lack of quality and operational standards, transportation, and storage of excessive inventory. Learn more about defects in this article.
5. Overprocessing – in the context of losses, should be understood as the effect of poorly designed processes or improperly selected equipment for the process. You can read more about this type of waste here.
6. Unnecessary movements – is the effect of poor ergonomics of workstations, inadequate layout of the work area – the arrangement of machinery and equipment, poorly organized workspace.
7. Waiting – is one of the least harmful types of waste. Waiting occurs when we wait for an order, a process, a machine, a forklift, documentation, or a decision to be made.

Practical example

Practical examples of 7 types of waste

The practical examples of defined wastes, otherwise known as muda involve:

• employees (i.e., waiting, unnecessary movements),
• processes (i.e., overproduction, unnecessary processing),
• and materials (i.e., inventory, repairs and shortages, transportation).

Wastes have been identified – what next?

After realizing what losses we may be facing in the company, the next step should be to eliminate them. Companies that implement Lean Manufacturing focus on identifying and eliminating waste on a consistent, daily basis. It is on average around 1% depending on the industry. What does this mean? This means that 99% of activities are unnecessary activities for which the customer will not pay – so they are nothing but a loss for us. ” Leaner” production and elimination of waste provides a competitive advantage in the market and affects the achievement of higher profits of the company.

If you want to learn more about the methods and tools used to identify losses – read the article … or watch our online training course!