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 (illustrative)
A print shop team walks an order from intake to shipping and logs 20 wastes. Waiting is the most common, with 6 entries, mostly jobs held for approval. Motion comes next with 4, from walking to a distant cutter, and defects third with 3 reprints from unclear specs. Moving the cutter and adding an approval checklist removes the top three. On the next walk a month later, the team logs 9 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.
Ohno's own terms were slightly different: overproduction, waiting, conveyance, processing, inventory, motion and correction. Conveyance is transport, processing is over-processing and correction is defects.
Later writers added an eighth waste, unused talent or skills: not using people's knowledge and ideas. Jeffrey Liker's The Toyota Way discusses it as unused employee creativity. 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.
How to run a waste walk
A waste walk is a planned walk along the value stream to find these wastes before anyone picks a fix. Follow one product or order from start to finish, and ask the people doing the work what slows them down. Seven questions cover most of it:
Waste walk
- Where does work wait? Queues before machines, inspections, approvals or forklifts.
- Where does work move? Trace parts, people, tools, paperwork and data.
- Where is work redone? Repairs, corrections, retests and repeated data entry.
- Where does stock pile up? Ask what uncertainty each pile protects against.
- Where do people search? Hunting for tools, parts, files or decisions points to a missing standard.
- Where do methods differ? Two people doing the same job two ways often means missing training or an outdated instruction.
- Where do people work around the process? Workarounds show the gap between the official method and the real one.
Opinion
Shipping is disorganized.
Observation
Operators searched three locations for the right cartons before packing.
Write down what you see, not what you think of it. A specific observation points to a fix, while an opinion starts an argument. Then rank what you found by safety, quality, customer impact and how often it happens, and pick one problem to work on.
The eight wastes outside the factory
The same eight wastes show up in offices, software, healthcare and logistics. Each has a usual first move:
| Waste | What it looks like | Where to start |
|---|---|---|
| Defects | Errors, returns, bad data, failed checks | Build quality into the step and fix the root cause |
| Overproduction | Making too much or too early, reports nobody reads | Work to demand and cut batch sizes |
| Waiting | Idle people, stalled approvals, late materials | Remove the bottleneck and set clear triggers |
| Non-utilized talent | Ideas ignored, skills unused | Involve people in solving problems |
| Transportation | Moving products or files with no need | Redesign the layout or the flow of information |
| Inventory | Excess stock, backlogs, unfinished work | Match work in progress to demand |
| Motion | Searching, walking, clicking, switching systems | Organize tools, workspace and digital files |
| Extra processing | Duplicate checks, extra reports, repeated data entry | Simplify rules and remove duplication |
Defects
Errors, returns, bad data, failed checks
Where to start: Build quality into the step and fix the root cause
Overproduction
Making too much or too early, reports nobody reads
Where to start: Work to demand and cut batch sizes
Waiting
Idle people, stalled approvals, late materials
Where to start: Remove the bottleneck and set clear triggers
Non-utilized talent
Ideas ignored, skills unused
Where to start: Involve people in solving problems
Transportation
Moving products or files with no need
Where to start: Redesign the layout or the flow of information
Inventory
Excess stock, backlogs, unfinished work
Where to start: Match work in progress to demand
Motion
Searching, walking, clicking, switching systems
Where to start: Organize tools, workspace and digital files
Extra processing
Duplicate checks, extra reports, repeated data entry
Where to start: Simplify rules and remove duplication
Removing waste does not mean asking people to work faster. Ask what gets in the way of valuable work, and change the design.
| 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 |
Guides on this topic
- Lean healthcare: principles, tools and how to startLean healthcare applies lean methodology to patient care. See the principles, hospital wastes, tools, patient flow and how to start in a clinic or ward.Read the guide
- Gemba walk checklist: questions, form and routinesA gemba walk checklist with before, during and after steps, question sets for flow, safety and quality, a simple form layout and mistakes to avoid.Read the guide
- Lean construction: principles, techniques and how to startLean construction applies lean thinking to building projects. Learn the principles, the eight wastes on site, the Last Planner System and how to start.Read the guide
- Lean Six Sigma yellow belt: training, role and valueA lean six sigma yellow belt supports improvement projects with basic tools. See what yellow belt training covers and how it differs from green belt.Read the guide
Sources
Books and papers show their publication year. Web pages show the month we last checked them.
- 1.Taiichi Ohno, Toyota Production System: Beyond Large-Scale Production (Productivity Press, 1988)
- 2.Jeffrey K. Liker, The Toyota Way: 14 Management Principles from the World's Greatest Manufacturer (McGraw-Hill, 2004)