The fundamental problem arises from the nature of work at Levi 's factories. Unlike an assembly line for cars or copiers, speed in garment-making relates directly to a worker's skill and stamina for the grueling, repetitive motions of joining and stitching fabric. The workers in Levi 's plants operate machines that perform specific tasks: pocket setter, belt looper, fly stitcher, among others. Some employees work much faster than others.