QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL

Qual. Reliab. Engng. Int. 2001; 17(4): iii–iv (DOI: 10.1002/qre.420)

EDITORIALBEYOND SIX SIGMA

A July 21 1998 article in USA Today stated that‘Today, depending on whom you listen to, Six Sigmais either a revolution slashing trillions of dollars fromcorporate inefficiency or it’s the most maddeningmanagement fad yet devised to keep front-line workerstoo busy collecting data to do their jobs’. Since thatstatement was made, Six Sigma has emerged as auseful strategy for improving operational performancein many different types of organizations. There havebeen notable successes, such as those at GeneralElectric and Allied Signal/Honeywell. For example, inthe most recent GE annual report (2000) Jack Welchwrote ‘Six Sigma has galvanized our company withan intensity the likes of which I have never seen in my40 years at GE’.

While Six Sigma has its critics, there is not muchdoubt that it can be a very useful framework fordriving operational improvement, reducing variabilityand improving the quality and reliability of products.Why has Six Sigma been successful, when some ofits predecessors, such as TQM, are dead? I think thatthere are two reasons. First, Six Sigma is focusedon achieving business goals. The project orientationof a typical Six Sigma effort is crucial, and thetypical project returns in excess of $50 000. Manyof them have even greater impact. The structure ofGreen Belts, Black Belts, Master Black Belts andChampions is very effective at identifying problems,and then putting teams together to solve them. TQMefforts rarely had any real project or implementationcomponent, and it was difficult if not impossible forupper management to find any significant contributionto the bottom line. With management’s preoccupationwith the bottom line, anything that does not contributewill not stay on the radarscope for long. The secondreason for Six Sigma success is the high level ofupper management involvement and commitment.Now I think that this comes about because ofthe business focus. If management sees measurablefinancial results accruing from Six Sigma, it is easierto become a proponent, and to commit the resourcesrequired for sustaining activities.

Everything has a life cycle, be it a naturalor physical process, a framework for processimprovement, or a management fad. Consequently,despite any real success it may have enjoyed tothe present, Six Sigma is going to have to evolveto maintain currency and effectiveness. So what isnext . . . Ten Sigma? I do not think so.

A natural evolution would be to expand thebase of problems and projects that encompass aSix Sigma effort. As examples, this could includesupply chain issues, scheduling, logistics, deeperpenetration into engineering design and development,the broad range of problems encompassing productionplanning and control, and the vast expanse of non-manufacturing operations that are an integral part ofmany businesses. Now there are companies that arecurrently doing some of this. For example, GE hasconducted successful Six Sigma activities at theirfinance and consumer credit units. Some organizationshave begun ‘Lean Enterprise’ programs that attacksome of the broader problem areas I mentionedabove. These initiatives could fold naturally into SixSigma. Indeed, many people are now beginning totalk about ‘Lean Sigma’. Personally, I hate this name,and hope that a better one evolves. A lot of the leaninitiatives that I have seen are not much more thanrecycled versions of some of the Just-In-Time ideasof the 1980s. In the long run, to really accomplishthe simultaneous objectives of Six Sigma and LeanEnterprise, practitioners will not only have to gain asolid understanding of additional statistical tools, butknowledge of industrial engineering and operationsresearch techniques, such as systems simulationand factory modeling, mathematical optimizationmethods, and queueing networks. This is a muchhigher level of knowledge than most Black Belts andMaster Black Belts currently acquire.

The future success of Six Sigma will requiredevelopment and education of more Master BlackBelts within most organizations. Furthermore, theseindividuals will have to have a broader and deeper skillset than is currently typical. The current generation of

Copyright 2001 John Wiley & Sons, Ltd.

iv EDITORIAL

Six Sigma Black Belts is basically trained to recognizeproblems that statistical methods could effectivelysolve and to attack these problems with a structuredproblem-solving process and a set of fairly basic tools.This will enable them to achieve good results for manyof the relatively simple problems that most companieshave. Fortunately, there is a lot of this ‘low-hangingfruit’ as the successes at GE and other organizationshave shown. But we have to start thinking nowabout developing the skills, talents and resources toeffectively carry on the effort once the low-hangingfruit is all picked. To a large extent, this is whySix Sigma has largely burned out at its birthplace,Motorola. This organization enjoyed great successfrom Six Sigma in the late 1980s and early 1990s.They cleaned up most of the simple problems, but did

not have a plan in place to sustain the effort once theseeasy problems were solved.

The time to start thinking about the evolution ofSix Sigma is now, because there is a danger that ifwe do not, in 10 years it will reside in the trash binwith TQM, Business Process Engineering, Quality isFree, Value Engineering, Zero Defects and the otherhalf-baked management fads of the last 50 years.That would be a shame, because unlike all of theseother efforts, Six Sigma actually can work very well,because it is based on sound statistical science andit is contained in an effective problem identificationand solution framework. However, it cannot be a staticframework if the success is to last.

DOUGLAS MONTGOMERY

Copyright 2001 John Wiley & Sons, Ltd. Qual. Reliab. Engng. Int. 2001; 17(4): iii–iv