Lean Thinking and the 8 Wastes

Lean thinking focuses on eliminating waste from work processes to improve efficiency and value. But before we dive into the eight types of waste, it’s important to define what waste actually means. In Lean terms, waste refers to any activity or step in a process that does not add value to the customer. Put simply, waste is anything that a customer is unwilling to pay for.

The concept of waste, known as Muda, was first developed by Taiichi Ohno, Chief Engineer at Toyota, as part of the Toyota Production System (TPS). Initially, there were seven recognized types of waste: Transportation, Inventory, Motion, Waiting, Overproduction, Overprocessing, and Defects. These are often remembered by the acronym TIMWOOD.

In the 1990s, a new waste was added—the underutilization of people’s skills—leading to the more commonly used acronym TIMWOODS. In this article, we will explore each of these wastes in more detail.

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1. Transportation Waste

Transportation waste refers to the unnecessary movement of materials, people, equipment, or products. Whether it's moving inventory or employees walking long distances, extra movement often leads to higher costs, potential damage to goods, and lost time.

Countermeasures: To reduce transportation waste, consider reorganizing workspaces to improve flow (e.g., a U-shaped production line), avoid overproduction, and ensure that materials are easily accessible.

2. Inventory Waste

Excess inventory is often seen as an asset, but it can cause a host of problems, including hidden defects, wasted capital, and longer lead times. The key issue is that excess inventory can mask production problems and prevent defects from being detected early.

Countermeasures: Reduce overproduction, purchase materials only when needed, and set up inventory systems that prevent unnecessary stockpiling.

3. Motion Waste

Motion waste is any unnecessary movement of people, tools, or machinery. In manufacturing, excessive motion not only wastes time but can also lead to physical strain and health issues.

Countermeasures: To minimize motion waste, ensure workstations are well-organized, tools and materials are within easy reach, and work tasks are ergonomically designed.

4. Waiting Waste

Waiting occurs when people, equipment, or materials are idle, waiting for the next step in the process. This can result from uneven workloads, insufficient equipment, or delayed information, leading to delays and inefficiency.

Countermeasures: To minimize waiting time, ensure a steady flow of work, balance workloads, and cross-train employees so they can step in when needed.

5. Overproduction Waste

Overproduction happens when goods are produced before they are needed, or in larger quantities than required. This results in unnecessary inventory, higher storage costs, and longer lead times.

Countermeasures: Implement a Just In Time approach, use Takt Time to match production rates to customer demand, and use a Kanban system to manage production flows.

6. Over-processing Waste

Over-processing happens when more work or resources are put into a product or service than the customer actually needs. This can include using higher-quality materials, more steps, or additional features that don't add value.

Countermeasures: Always focus on what the customer truly needs. Eliminate unnecessary steps, simplify processes, and ensure quality standards align with customer expectations.

7. Defects Waste

Defects refer to products or services that don’t meet the required standards, leading to rework or scrapping of items. This adds unnecessary costs and delays.

Countermeasures: Focus on preventing defects by identifying common issues, designing error-proof processes, and using standardized work practices to ensure quality.

8. Skills Waste (The 8th Waste)

The 8th waste is the underutilization of employees' skills, creativity, and potential. This happens when workers are not engaged in problem-solving or improving processes, or when they are given tasks that don’t match their abilities.

Countermeasures: Engage employees by encouraging them to share ideas, provide training opportunities, and ensure that they are placed in roles that match their skills and talents.

Identifying and Eliminating Waste

The first step to eliminating waste is recognizing it. One effective tool for this is Value Stream Mapping (VSM), which helps visualize the flow of materials and information across a process. VSM highlights both value-adding and non-value-adding activities, enabling teams to focus on waste reduction.

To begin eliminating waste, start with the end customer in mind. Map the value stream from the customer’s perspective, identify wasteful activities, and develop strategies to reduce or eliminate them. Engage frontline employees in the process, as they are often the best source of ideas for improvement.

By continuously challenging your team to identify and eliminate waste, you foster a culture of ongoing improvement, where waste reduction becomes part of the daily routine, ultimately driving greater efficiency and customer value.

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