Lean manufacturing is a concept that attacks waste within a plant or company. In a lean methodology, waste elimination results in cost reduction. "Waste is anything that does not contribute to transforming a part to your customer’s needs," says Dr. Jeffrey Liker, a senior consultant for Optiprise Inc. (Holland, MI), who points out that there are 7 basic wastes in manufacturing:

Over production: producing more material than is needed before it is needed is the fundamental waste in lean manufacturing; material stops flowing.

Producing defective products: defective products impede flow and lead to wasteful handling, time and effort.

Inventories: material sits taking up space, costing money and potentially being damaged. Problems are not visible.

Motion: any motion that does not add value to the product is waste.

Processing: extra processing not essential to value-added from the customer point of view is waste.

Transportation: moving material does not enhance the value of the product to the customer.

Waiting: material waiting is not material flowing through value-added operations.

Source: Optiprise Inc.