Eliminating waste, or muda, from processes is a core concept of lean. Most of us know the seven types of waste (see below), yet the trick is “learning to see” these wastes that often are ubiquitous parts of our operations. Below is a list of common symptoms for each waste. If you see the symptom, you may have an opportunity to eliminate the underlying waste.

• Defects - Plant “hospitals”, rework loops, customer returns and complaints, cost overruns for raw materials or labor, 100% inspection (in plant or at the customer).

• Overproduction - Often called the “mother of all muda” since it can cause or increase the incidence of the other six wastes. Look for excess inventory, AS/RS systems, large batch size, inability to meet customer demand, long or complex setups, low awareness of takt time (customer demand rate), poor quality, inflexibility, disjointed operations within a process.

• Transportation - Fork lifts, carts, AR/RS systems, AGV systems, consumption of envelopes, boxes, shipping labels, long lead times, aisles, conveyors.

• Waiting - Bins, queuing areas, waiting areas, chairs, in/out boxes, large batch sizes, long lead times, pallets, boxes, envelopes, stuff in the aisles.

• Inventory - Look for reasons that people would build inventory as a quick fix to a problem: parts shortages, mura, defects, long lead times, labor standards, idle time, lack of clear build signal.

• Motion - Safety issues like repetitive strain injuries, falls, long or inconsistent cycle times, misplaced tools, cranes, lifts and other material handling equipment

• Overprocessing - Conformance issues with tolerances, fit, finish. Long cycle times, worker performance issues, scrap rates, standard material specifications