Seven classics and an eighth
The original list of losses in the Toyota Production System has seven items. Many companies, however, work with eight wastes. The addition is unused talent: the intelligence, experience and initiative of people who are left out of problem solving.
This text does not repeat the detailed description of the first seven. That is in The 7 Wastes of Lean. Here the focus is the eighth, the mnemonic for memorizing the list and a method for seeing each loss on the shop floor.
An honest note: the eight-item version is a widespread practice in Western Lean literature, not a fixed list from Taiichi Ohno. The original seven remain the foundation. The eighth is a useful extension.
The eight wastes in one table
The table summarizes each loss with a typical sign that it is present.
| # | Waste | In one sentence | Sign at the gemba |
|---|---|---|---|
| 1 | Transportation | Moving material without adding value | A forklift crossing the plant to carry a part between neighboring steps |
| 2 | Inventory | Material sitting beyond what is needed | Pallets of semi-finished goods waiting for the next operation |
| 3 | Motion | Operator movements that do not transform the product | A person walking to fetch a tool or chasing documents |
| 4 | Waiting | A person or machine idle, waiting for something | An operator watching the machine cycle or waiting for quality release |
| 5 | Overproduction | Producing more, or earlier, than the customer asks for | Large lots made to take advantage of the setup changeover |
| 6 | Over-processing | Doing more than the customer values | Finishing beyond the specification, redundant approvals |
| 7 | Defects | Product that requires rework or disposal | A full rework area, scrap bin and final inspection |
| 8 | Unused talent | Ignoring people's knowledge and creativity | Suggestions with no response, an operator with no voice in workstation decisions |
The first seven are process losses. The eighth is a management loss: the company pays a salary for the whole person and uses only the hands.
A mnemonic to remember the list
To memorize it, many teams use the acronym TIMWOODS, formed by the initials of the wastes in English:
- Transportation: moving material unnecessarily.
- Inventory: excess material.
- Motion: unnecessary movement of people.
- Waiting: idle time.
- Overproduction: producing more than needed.
- Over-processing: doing more than the customer values.
- Defects: rework and scrap.
- Skills: unused skills.
Another common acronym is DOWNTIME, which reuses the same ideas in a different order. Choose just one and put it on the team board. The goal is not to memorize for its own sake. It is to have a shared vocabulary on observation walks.
The eighth waste: unused talent
Unused talent appears when the organization wastes what people know and could learn. The person who operates the machine every day knows its failures better than any consulting project.
The most frequent symptoms are easy to recognize:
- A skilled operator doing only repetitive tasks, with no part in adjustments.
- Improvement suggestions that vanish with no feedback within two weeks.
- Method decisions made only by the office, without consulting the workstation.
- Training given once and never applied.
- High turnover in areas where no one is heard.
This is the most expensive and least visible waste, because it does not show up in any inventory or scrap report. It hides behind the other seven: almost every physical waste persists because someone who saw it was not listened to.
How to identify all eight on the shop floor
Identifying waste is an observation skill. Follow this simple routine.
- Choose a short flow. One product, from receiving to shipping, or one workstation.
- Go to the place. Take a gemba walk with paper in hand, no laptop.
- Time it without judging. Note how long the product sits still and how long it is being transformed.
- Classify each loss. Use the table above and write the waste number next to the record.
- Ask the person at the workstation. The question is: what gets most in the way of your work here? The answer helps measure the eighth.
- Prioritize by impact and ease. Start with the losses that are easy to attack and that disrupt the most people.
A practical rule: if the activity does not transform the product, is not something the customer would pay for and is not required by regulation, treat it as a candidate for waste.
How the wastes feed each other
The eight do not live in isolation. One feeds the other, which is why fighting them one by one usually yields little.
- Overproduction generates inventory, which generates transportation and occupied space.
- Defects generate rework, which generates waiting and extra motion.
- Waiting often hides a bottleneck, the subject of the Theory of Constraints.
- Unused talent prevents anyone from noticing and cutting the others.
To see the chain across the whole flow, use value stream mapping. The map shows where the product waits and where each loss comes in. It is also worth reading about muda, mura and muri, which explains why waste is only one of three families of loss.
Next step
This week, choose a workstation and observe it for 30 minutes. Note each occurrence with the waste number, from 1 to 8. At the end, add up by category and present the result to the workstation team.
Then run the improvement cycle with the person who understands the work best. For details on the rest of the list, also read Wastes in manufacturing and the article on 10 practical waste elimination scenarios.
Frequently asked questions
What are the 8 wastes of manufacturing?
Transportation, inventory, motion, waiting, overproduction, over-processing, defects and unused talent.
Is the eighth waste part of the original Toyota system?
No. The original list has seven items. Unused talent is an extension that is widespread in Western Lean practice.
What does TIMWOODS mean?
It is a mnemonic with the initials of the eight wastes: Transportation, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects and Skills.
How do I start identifying waste?
Observe a short flow on site, time the idle periods, classify each loss and listen to the person at the workstation.
Keep learning
Sources
- OHNO, T. O Sistema Toyota de Produção: além da produção em larga escala. Porto Alegre: Bookman.
- LIKER, J. O Modelo Toyota. Porto Alegre: Bookman.
- Lean Enterprise Institute. Lean Lexicon: Seven Wastes. https://www.lean.org/lexicon-terms/seven-wastes/
- Lean Enterprise Institute. Lean Lexicon: Waste. https://www.lean.org/lexicon-terms/waste/
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About the author
Lean Manufacturing & Behavioral Management Specialist
Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.
