From the Lean Lexicon
Taiichi Ohno’s categorization of the seven major wastes typically found in mass production: 1. Overproduction: Producing ahead of what’s actually needed by the next process or customer. The worst form of waste because it contributes to the other six. 2. Waiting: Operators standing idle as machines cycle, equipment fails, needed parts fail to arrive, etc. 3. Conveyance: Moving parts and products unnecessarily, such as from a processing step to a warehouse to a subsequent processing step when the second step instead could be located immediately adjacent to the first step. 4. Processing: Performing unnecessary or incorrect processing, typically from poor tool or product design. 5. Inventory: Having more than the minimum stocks necessary for a precisely controlled pull system. 6. Motion: Operators making movements that are straining or unnecessary, such as looking for parts, tools, documents, etc. 7. Correction: Inspection, rework, and scrap.
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