The 8 Wastes of Lean (TIMWOODS), With Examples

5 min read · Updated July 2026

In Lean, "waste" (muda) is anything that consumes resources without adding value for the customer. There are eight classic types, remembered by the acronym TIMWOODS. Learning to see them is the first skill of continuous improvement.

The eight wastes

• Transport — moving materials, files or information more than necessary (e.g. shuttling paperwork between offices).
• Inventory — more stock or work-in-progress than needed (e.g. a backlog of half-finished cases).
• Motion — unnecessary movement of people (e.g. walking to a shared printer across the building).
• Waiting — idle time between steps (e.g. waiting for sign-off before work can continue).
• Overproduction — making more, or earlier, than the customer needs (e.g. printing reports nobody reads).
• Overprocessing — doing more work than the customer values (e.g. triple-checking low-risk data).
• Defects — errors and rework (e.g. re-keying an order because of a mistake).
• Skills — underusing people’s knowledge and ideas (the "eighth waste").

Why overproduction is the worst

Overproduction is often called the root waste because it creates the others — it builds inventory, needs transport and storage, and hides defects. Making only what is needed, when it is needed, removes a cascade of downstream waste.

How to spot waste

Go to where the work happens and watch. Ask of every step: would the customer pay for this? Waiting, rework and movement are usually the easiest to see first — and a value stream map makes them impossible to ignore.