Role of OEE in Lean Manufacturing

The Lean methodology focuses on removing non-value-adding activities and waste to reduce complexity and cost. The Lean approach provides foundation for operational excellence by process standardization, worker empowerment and instills a culture of continuous improvement.

All employees are involved in continuously reviewing and improving efficiency throughout a process or value chain when Lean techniques are in place. Lean techniques may include visual controls to help operators identify the right times to adjust equipment, or preventive maintenance to reduce the number of equipment failures by proactively maintaining equipment.

OEE, a measurement used in Total Productive Maintenance programs, is a metric commonly found in Lean Manufacturing. The OEE metric and Lean process can help manufacturing answer three questions:

  • How often is the machine available to run?
  • How fast is the machine when running?
  • What is the count of acceptable parts made?

In addition to the three questions are six areas of losses that can affect the OEE and its three components. Breaking down the losses to these categories helps the Lean manufacturing team prioritize improvements.

Breakdown Losses

Breakdown losses falls under the OEE “availability loss” and Lean’s “unplanned stops” – sudden or unexpected equipment downtime that makes the machine less available. Contributing factors may include:

  • Major mechanical failures
  • Electrical system failures
  • Structural failure

Set-up & Adjustment Losses

Set-up and Adjustment Losses are an availability loss that falls under Lean six big loss of “planned stops”. The degree of loss depends on factors such as:

  • Standards process
  • Tooling consistency and quality
  • Skill-level of operator

Idling & Minor Stoppages

Production is interrupted by a temporary malfunction or when the machine is idling. This is an OEE performance loss and falls under the Lean “small stops”. Contributing factors include:

  • Defective products resulting from a line shutdown
  • Operator on other machine or other tasks
  • Temporary equipment malfunction

Reduced Speed Losses

This stage refers to the difference in equipment design speed and the actual operating speed. It is an OEE performance loss and a Lean “slow cycles”. Factors include:

  • Mechanical problems
  • Risk of making unacceptable parts at higher speeds
  • Operator training

Process Defects

Process defects occur during the stages of production – from machine start-up, warm-up, and “learning phase”. This stage is an OEE quality loss and “production rejects” in the Lean stages. The degree of loss depends on factors such as:

  • Maintenance of equipment
  • Tooling
  • Raw Material
  • Operator skill level

Reduced Yield

Losses in quality caused by malfunctioning equipment or tooling. An OEE quality loss, the degree of loss depends on factors such as:

  • Maintenance of equipment
  • Tooling
  • Raw Material