The late Taiichi Ohno first articulated this philosophy and
implemented it in Toyota's production system. He classified
sources of waste as follows (8 added by Womack and Jones
1996): (1) Defects in products; (2) Overproduction of goods not
needed; (3) Inventories of goods awaiting further processing or
consumption; (4) Unnecessary processing; (5) Unnecessary
movement of people; (6) Unnecessary transport of goods; (7)
Waiting by employees for process equipment to finish its work
or for an upstream activity to complete; and (8) Design of goods
and services that fail to meet user's needs.