Key takeaways
Short answer: The Six Big Losses are the equipment-level losses that OEE decomposes — breakdowns, setup and adjustment, micro-stops, reduced speed, startup scrap and production scrap. The Seven Wastes (muda) are the flow-level losses lean attacks — overproduction, waiting, transport, over-processing, inventory, motion and defects. One framework is about how effectively a machine runs; the other is about how value flows through the whole stream. They overlap at the edges but answer different questions. See also oee loss tree vs pareto.
The Six Big Losses are the canonical equipment losses that map directly onto OEE. They explain exactly where a machine's effectiveness leaks, and each maps to one of OEE's three terms.
The Seven Wastes (muda) come from the Toyota Production System and describe non-value-added activity across the whole value stream, not just at one machine. They are about flow — how work moves (or fails to move) from raw material to customer.
A team improving a single bottleneck machine reaches for the Six Big Losses — and rightly so: it breaks down (Availability), runs slow with micro-stops (Performance) and produces startup scrap (Quality). The framework maps the machine's losses onto OEE and drives the fix. But when the same plant tries to cut a nine-day lead time, the Six Big Losses are the wrong frame — the lead time is mostly waiting and inventory between machines, which are Seven Wastes, not equipment losses. Each problem needed its own framework; using the machine frame on a flow problem would have missed the days of waiting entirely.
The Six Big Losses live at the machine and map to OEE; the Seven Wastes live across the value stream and map to flow and lead time. They overlap — defects and scrap appear in both, and a breakdown causes waiting downstream — but their scope is different. The Six Big Losses ask "why is this machine ineffective?"; the Seven Wastes ask "why doesn't value flow?"
The two frameworks meet at the machine. A breakdown (a Six Big Loss) creates waiting (a Seven Waste) downstream; reducing micro-stops improves both OEE Performance and flow. The strongest programs use the Six Big Losses to drive machine-level OEE and the Seven Wastes to drive value-stream flow, recognising that a fix in one often helps the other.
1. Using the Six Big Losses on a flow problem. You miss the waiting and inventory between machines.
2. Using the Seven Wastes to fix one machine. The equipment-specific losses need the OEE frame.
3. Assuming they are the same list. They overlap but have different scope and purpose.
4. Picking a framework by habit. Match the frame to whether the problem is machine effectiveness or value flow.
The Six Big Losses are literally the structure of an OEE loss tree — they decompose the OEE gap into actionable categories. The Seven Wastes sit one level up, explaining the flow losses that connect machines. Use the Six Big Losses to drive OEE, and the Seven Wastes to make sure the whole stream, not just one machine, is improving.
See how Fabrico captures this automatically on your lines — explore OEE for manufacturing or book a demo.
No — the Six Big Losses are equipment losses behind OEE; the Seven Wastes are flow losses behind lean.
The Six Big Losses — they map directly onto OEE's Availability, Performance and Quality.
For flow, lead time and value-stream problems across the whole process.
Yes — defects and scrap appear in both, and equipment losses cause flow waste downstream.
Yes — Six Big Losses for machine OEE, Seven Wastes for value-stream flow.
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