The Six Big Losses in Lean Manufacturing

Understanding the Six Big Losses and Maximizing Total Team Effectiveness in Manufacturing

Manufacturing efficiency relies heavily on machines, and ensuring optimal machine performance is essential for maintaining maximum productivity. One critical concept in understanding machine efficiency is the Six Big Losses, which identifies the primary factors that cause reduced equipment performance. These losses directly impact Overall Equipment Effectiveness (OEE), a key metric used to measure manufacturing productivity.

In this blog, we’ll explore the Six Big Losses and introduce Total Team Effectiveness (TTE), a variation of OEE that accounts for both machine performance and the human element within production teams.

What are the Six Big Losses?

The Six Big Losses are common categories of productivity loss in manufacturing that directly affect machine efficiency. These losses can be broken down into three main categories: stoppage, speed losses, and quality losses. Let’s examine each of these categories and their contributing factors:

1. Stoppage Losses

Stoppage losses refer to machine downtime, which can be both planned and unplanned. These losses occur when machines are not running, either because they are scheduled for maintenance or because unexpected issues arise.

1-Planned Stoppages: This includes time taken for activities such as machine changeovers, routine maintenance, cleaning, and setups. These stoppages are part of regular operations and are planned in advance.

2-Unplanned Stoppages: These occur due to unexpected machine failures, breakdowns, or waiting times between production steps. Unplanned downtime can significantly disrupt production schedules and lower OEE.

2. Speed Losses

Speed losses occur when machines are not operating at their maximum potential speed. These losses are often overlooked, but they contribute significantly to reduced output.

3-Planned Speed Losses: These losses are caused by activities such as machine warm-up times or initial setups, where machines are deliberately run at slower speeds to ensure quality.

4-Unplanned Speed Losses: These happen when machines experience minor stops or reduced operating speeds due to issues such as equipment wear and tear, operator inefficiency, or lack of material supply.

3. Quality Losses

Quality losses are the result of defects or subpar products being produced, which require rework or rejection. These losses affect overall production quality and lead to wasted time and materials.

5-Planned Quality Losses: Initial product quality issues, such as startup rejects or test runs, are part of planned quality losses. These losses may occur during the first few units produced when adjusting a machine or setting up new materials.

6-Unplanned Quality Losses: Unplanned losses include scrap products, rework, and defects that occur due to operator errors, machine malfunctions, or inconsistent material quality. These issues directly affect the final product’s acceptability and can result in costly delays.

Total Team Effectiveness (TTE): Combining Human and Machine Performance

While OEE focuses primarily on machine performance, Total Team Effectiveness (TTE) introduces the human element, measuring not only machine efficiency but also the contribution of employees to overall productivity. TTE recognizes that a well-functioning team is crucial to optimizing the production process.

Here are the key components of TTE:

1. Availability (Team-Based)

In TTE, availability considers the time that the team is present and able to work. This is calculated by subtracting planned absences, such as vacations or sick leave, from the total available working hours.

1. Planned Availability Losses: These include scheduled absences like holidays, personal leave, or any other planned time away from work.
2. Unplanned Availability Losses: These include unplanned absences such as sick days, late arrivals, or emergency leave, which can affect the team’s overall output.

2. Speed (Team Efficiency)

TTE also measures how efficiently the team operates in terms of speed. This is calculated by subtracting stoppages related to human factors (e.g., waiting for materials, coordination issues, or system downtimes) from the total available time.

3. Planned Speed Losses: Team members may need to slow down for training, process learning, or working on new equipment, leading to planned speed losses.
4. Unplanned Speed Losses: These are disruptions in the team’s workflow due to communication issues, lack of materials, or unanticipated delays in production.

3. Quality (Human Contribution to Product Quality)

In TTE, quality refers to how consistently the team can meet product quality standards. This metric looks at how often mistakes or errors made by employees lead to rework or rejected products.

5. Planned Quality Losses: Employees may require additional time to adjust to new processes or equipment, leading to a temporary decline in product quality.
6. Unplanned Quality Losses: These occur due to human errors, such as incorrect machine settings or improper handling of materials, which lead to product defects or rework.

Improving OEE and TTE: Reducing the Six Big Losses

Both OEE and TTE can be improved by targeting the Six Big Losses and addressing the human factors that impact productivity. Here are some practical steps you can take:

1. Autonomous Maintenance: Train frontline operators to perform regular machine checks, cleaning, and minor repairs. This helps reduce unplanned stoppages and keeps machines running smoothly.
2. Preventive Maintenance: Schedule regular maintenance for critical components to prevent unexpected breakdowns and prolong equipment life.
3. Training and Skill Development: Invest in employee training to minimize human errors, improve efficiency, and boost overall quality.
4. Visual Management: Use visual cues and metrics on the shop floor to quickly identify issues with machine availability, speed, or quality. This helps teams address problems in real time.
5. Kaizen and Continuous Improvement: Implement small, continuous improvements to eliminate waste and enhance both machine and team performance.

Conclusion

By understanding the Six Big Losses and applying Total Team Effectiveness, organizations can optimize both machine performance and workforce productivity. Identifying and addressing the root causes of losses in availability, speed, and quality leads to better production efficiency, fewer bottlenecks, and higher output.

Whether you’re looking to improve your OEE score or increase TTE within your team, focusing on these key metrics will help you build a more resilient and productive manufacturing process. With a solid strategy in place, your team can reduce losses, maintain consistent output, and drive operational excellence.