Six big losses is the classic TPM loss framework that categorizes the primary causes of OEE erosion across downtime, speed loss, and quality loss - it provides a practical map for diagnosing where production capability is being lost.

What Is Six big losses?

• Definition: Six standardized loss types: breakdowns, setup and adjustment, idling and minor stops, reduced speed, process defects, and reduced startup yield.
• Category Mapping: The first two impact availability, the next two impact performance, and the last two impact quality.
• Analytical Use: Converts diverse operational issues into a common taxonomy for trend and Pareto analysis.
• Improvement Link: Each loss category maps to specific engineering and maintenance countermeasures.

Why Six big losses Matters

• Problem Structuring: Prevents vague discussions by forcing losses into measurable categories.
• Prioritization Speed: Teams can quickly identify which loss class dominates OEE decline.
• Cross-Site Consistency: Shared taxonomy improves benchmarking across lines and factories.
• Program Focus: Helps avoid over-investment in low-impact activities.
• Training Value: Creates common language between operators, technicians, and engineers.

How It Is Used in Practice

• Loss Coding: Ensure every stop and quality event is tagged to one of the six categories.
• Pareto Reviews: Track cumulative loss by category and shift resources to highest-impact buckets.
• Countermeasure Library: Maintain standard response playbooks aligned to each loss type.

Six big losses is a proven framework for OEE diagnostics and action planning - classification discipline makes improvement work faster, clearer, and more scalable.