Eight Wastes:

Taiichi Ohno originally enumerated seven wastes (muda) and later added underutilized people as the eighth waste commonly found in physical production.
The eight are:
1. Overproduction ahead of demand;
2. Waiting for the next process, worker, material or equipment;
3. Unnecessary transport of materials (for example, between functional areas of facilities, or to or from a stockroom or warehouse);
4. Over-processing of parts due to poor tool and product design;
5. Inventories more than the absolute minimum;
6. Unnecessary movement by employees during the course of their work (such as to look for parts, tools, prints or help);
7. Production of defective parts;
8. Under-utilization of employees’ brainpower, skills, experience and talents.