Any activity that uses up equipment,  materials, parts, space, employee time, or other resources beyond the minimum  amount required for productive operations. This can include waiting,  accumulating semi-processed features, reloading, passing materials from one  person to another, and other non-productive processes. The seven categories  of waste that are usually targeted for elimination in businesses are  overproduction, waiting for machines, transportation time, process time,  excess inventory, excess motion, and defects. In product development, waste  can refer to anything that adds cost or time to the development process  without adding value from the customer's perspective. This could include  unnecessary features, inefficient processes, or delays caused by rework or  insufficient data. By definition, waste is anything that doesn't contribute  to the final product or service meeting the customer's needs. Therefore,  reducing or eliminating waste is critical in any product development effort.