The Pitfalls of Six Sigma [the broken link was removed]:
Six sigma has strong advocates in the manufacturing world for its ability to help factories get lean, but many companies are feeling that their time and financial investment in six sigma has been wasted. Problems with implementation have caused financial and organizational setbacks. Some companies are strongly suggesting, and at times actually demanding their suppliers to adopt six sigma in their operations or run the risk of losing business. Many organizations have combined their lean initiatives with six sigma and are progressing well, while others with poor implementations and abandoned programs risk being left in the dust.