Lean teams use the eight wastes as a lens for seeing problems. Naming waste makes it easier to spot during gemba walks and value stream mapping. Removing waste shortens lead time and frees people for value-adding work.
Where it comes from
Taiichi Ohno described seven wastes as part of the Toyota Production System. Many practitioners later added non-utilized talent, giving the eight wastes used today.
At a glance
The 8 wastes (DOWNTIME)
Swipe sideways to see the whole diagram.
How to apply The 8 Wastes of Lean
- 1
Learn the eight categories
Teach the team each waste with examples from your own process. Local examples are easier to remember than generic ones.
- 2
Choose a process to study
Pick one value stream or area with a clear start and end. Keep the scope small enough to observe in one session.
- 3
Go and observe
Walk the process and note each waste you see, tagged by category. Follow the product, the information and the people.
- 4
Quantify the biggest wastes
Estimate time, distance, inventory or defects for the most visible items. Rough measurement is enough to prioritize.
- 5
Find root causes
Ask why each waste exists. Overproduction, for example, often comes from large batches or unreliable equipment.
- 6
Remove waste and standardize
Run small experiments to eliminate the top items. Update standard work so the waste does not creep back.
Worked example
A print shop team walks an order from intake to shipping. They log reprints from unclear specs, jobs waiting for approval and operators walking to a distant cutter. Moving the cutter and adding an approval checklist removes three of the most visible wastes.
Common mistakes
- Listing wastes without measuring or fixing any of them.
- Mistaking necessary non-value-added work, like legal checks, for pure waste to delete.
- Using waste hunts to cut headcount, which makes people stop pointing out waste.
When The 8 Wastes of Lean is not the right tool
Spotting waste is only a starting point. Naming a waste does not remove it; that takes a method such as PDCA.
Some activity that adds no value is still required, such as legal checks. Reduce it where you can, but do not remove it.
The 7 wastes
Taiichi Ohno described seven wastes (muda) at Toyota: transport, inventory, motion, waiting, overproduction, over-processing and defects. Each uses time or resources without adding value the customer would pay for.
Later writers added an eighth waste, unused talent or skills: not using people's knowledge and ideas. That gives the 8 wastes most lean training uses today.
TIMWOODS
TIMWOODS is one memory aid for the 8 wastes: Transport, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects and Skills.
DOWNTIME
DOWNTIME is another memory aid for the same list: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion and Extra-processing. Teams pick whichever is easier to remember; the wastes are the same.
Seven wastes and the eighth
Taiichi Ohno described seven wastes: overproduction, waiting, conveyance, processing, inventory, motion and correction.
Many lean practitioners add an eighth, unused talent. Jeffrey Liker's The Toyota Way discusses it as unused employee creativity.
| Term | Meaning | Example |
|---|---|---|
| Muda | Waste: activity that adds no value | Parts waiting between steps |
| Mura | Unevenness in the flow of work | Orders bunched at month end |
| Muri | Overburden of people or equipment | A machine run beyond its rated speed |