Six-Sigma: Lessons from the Black Belts

Through the use of a structured questionnaire, this paper presents the results of several black belt interviews. The lessons are introspective in nature and reveal what works and what doesn’t, successes and set backs, attempts and accomplishments, frustrations and failures. A strong thread of optimism pervades their endeavors. The most difficult requirement in most undertakings is that of changing behavior within organizations and assigning dollar value to completed projects, the primary measure of organizational accomplishment. Five well-trained and experienced black belts representing four different companies share their experiences. The companies represented are General Electric, one of the pioneers in six-sigma; Hollingsworth and Vose, a non-fiber textile manufacturer; BTR (later BTR Siebe), an automation and controls company; and Celanese, a synthetic fiber manufacturing plant. Three of the persons interviewed had been working full time as black belts in their companies. Two others work part time as black belts along with full-time positions, as quality manager in one case and maintenance engineer in another. To maintain confidentiality, particular projects are mentioned without specific reference to the firms in which they were undertaken. In three instances, the black belts are no longer with the firms that shaped their experiences. The other two black belts are still employed in the businesses that gave them their start. Background The name six-sigma comes from statistics and literally means six standard deviations. It refers to a process design or process improvement goal stated in terms of the properties of the normal distribution. Simply stated, that goal is to make the natural variation of the outputs of a particular production process half the product specification limits such that even if the process mean wanders around a bit, the number of defects expected will still be near zero. Here, “outputs” does not really denote the entire good