Overall Equipment Effectiveness (OEE) Calculator

Historical Background

The concept of Overall Equipment Effectiveness (OEE) was popularized by the introduction of Total Productive Maintenance (TPM), developed by Seiichi Nakajima in Japan. It became a crucial metric in lean manufacturing, providing a comprehensive measure of how well equipment is utilized.

Formula

The formula to calculate Overall Equipment Effectiveness (OEE) is:

\[ OEE = \frac{IDCT \times GC}{PPT} \]

where:

• OEE is the overall equipment effectiveness,
• IDCT is the ideal cycle time (min/hours),
• GC is the good count or the number of pieces that satisfy quality requirements,
• PPT is the planned production time (min/hours).

Example Calculation

If you have a total good count of 1200 pieces, an ideal cycle time of 0.5 minutes per piece, and a planned production time of 700 minutes, the OEE is calculated as:

\[ OEE = \frac{0.5 \times 1200}{700} \approx 0.8571 \approx 85.71\% \]

Importance and Usage Scenarios

OEE is used to assess how effectively equipment is utilized in manufacturing. It helps identify areas where productivity can be improved, pinpointing the impact of downtime, speed losses, and quality issues. This metric guides continuous improvement and supports lean manufacturing principles.

Common FAQs

What is considered a good OEE score?

• A world-class OEE score is typically 85% or higher. However, most companies target gradual improvements rather than immediate world-class levels.

How is OEE used in production analysis?

• OEE highlights the combined effects of equipment availability, performance, and quality. It helps identify losses and provides insights to enhance efficiency.

What does the planned production time include?

• Planned production time includes all the time when the equipment should be running. This excludes planned downtime like breaks and maintenance.