Eliminating what are known as the Six Big Losses is one way to improve your overall equipment effectiveness (OEE).

If you work in manufacturing, you are constantly looking for ways to improve productivity.

Developed in 1971 at the Japanese Institute of Plant Maintenance, this model, which is based on total productive maintenance (TPM), serves as an effective framework for improving your operations and increasing shop floor efficiency.

The Six Big Losses provide an effective way to compare and prioritise production losses, resulting in more successful root cause identification and elimination. The concept of the “six big losses” in Lean manufacturing refers to six key areas of waste or inefficiency that can occur in a production process.

The six major losses can be divided into three categories: Availability, Performance, and Quality.

The reason for categorising each factor is that the potential causes are usually distinct. It is critical to identify and address these losses in order to improve productivity, reduce costs, and maximise value.

Availability Loss:

The first two of the Six Big Losses are associated with your score and have to do with keeping your process running as much as possible. If your availability score is low, investigate your run time and production time figures.

1. Equipment Failure

The first significant loss is created by equipment that does not operate while being scheduled for production, resulting in unscheduled downtime. This could be due to machine failure, tooling failure, or emergency maintenance stoppage.

2. Setup & Adjustments

Downtime when equipment is not functioning due to a changeover, machine and tooling modifications, or planned maintenance, as well as setup time and quality inspections, causes the second major loss.

Performance Loss:

This can be defined as the time when the machine is functioning but not at full speed. This is usually due to one of two factors: small stops or slow cycles. Addressing these two losses allows you to maximise your output. Check the consistency of your run time and cycle time data if your performance score is poor.

3. Minor Stops

A minor stop occurs when machinery shuts down for less than 10 minutes. They are frequently persistent and may occur many times every day. This type of loss is typically caused by minor issues, such as when a product becomes stuck in the conveyor belt. If these complications occur frequently, the machine’s effectiveness suffers significantly. Even though a minor stoppage is technically a time loss, it may not be recorded as such because it occurs for such a brief period of time.

4. Reduced Speed

When a machine runs at a slower speed than its ideal cycle time, this loss occurs. This can sometimes be the result of insufficient maintenance. Another possible explanation for this is that people are unaware that the equipment is designed to run at a different speed than its current production speed, or that the intended speed results in low-quality products.

Quality Loss:

Is the time during which the machine is not producing when products should be produced, usually caused by either breakdowns or waiting. due to changeovers. This also includes tasks such as resetting machines, adjusting settings, and preparing materials. Long changeover times lead to less flexibility, more inventory, and longer lead times.

5. Process Defects

Process Defects are responsible for damaged items produced during steady-state production. Since OEE measures quality from a First Pass Yield perspective, this covers both trashed and re-workable items. Process flaws are a source of quality loss.

6. Reduced Yield

Both quality losses account for the manufacture of defective parts, including tarnished and re-workable parts. Process defects typically arise during steady-state production and are due by incorrect equipment settings, operator errors, poor equipment handling, and expiration. The defective parts generated during the warm-up stage of production are accounted for by reduced yield. It is caused by inefficient changeovers, incorrect settings, or equipment that generates waste after commencement.

The Six Big Losses structure provides a clear way to improving your OEE score:

Working to decrease Availability Loss in the form of Equipment Failures or Setups and Adjustments protects you from unplanned pauses or downtime and minimises any planned stops.
Addressing Performance Loss caused by Idling, Minor Stops, and Reduced Speed avoids minor stops and slow cycles from accumulating.
Finally, reducing Quality Loss in the form of Process Defects and Reduced Yield minimises the quantity of unusable parts produced before to and during steady-state production.