What are the 7 types of waste in Lean?

In Lean, 7 types of waste (muda) are identified, which reduce process efficiency:

1. Overproduction — producing earlier or in greater quantities than needed.
2. Waiting — idle time for employees, equipment, or materials.
3. Unnecessary transportation — unnecessary movement of materials or information.
4. Excess processing — performing unnecessary actions or operations.
5. Excess inventory — accumulating materials or finished products beyond demand.
6. Unnecessary movements — unnecessary movements of workers, such as searching for tools.
7. Defects — producing defective items and the need for rework.

Eliminating these wastes helps to increase productivity and quality.