By G. Geoffrey Vining, professor and head of department of
statistics, Virginia Tech, and chair of ASQs Publications Management
It ASQs 2001 Annual Quality Congress in Charlotte, NC, I participated in a panel discussion, Six Sigma: Breakthrough Strategy or Management Fad? At that time, I claimed it was a little bit of both. I still hold those beliefs.
The two best things Six Sigma has accomplished is getting the serious attention of senior management and tying results to the bottom line. Of course, these two accomplishments are not unrelated.
Senior management speaks the language of money. Six Sigma is a structured approach for process and system improvement. Other process improvement programs tended to use such metrics as number of defects. Senior management would acknowledge achievements like significant reductions in defect rates but never fully appreciated the impact of lower defect rates.
Learning the lower defect rate saves millions of dollars a year has a real impact on senior managers. They begin to appreciate what a sound process improvement program can do for the company. In this sense, Six Sigma is truly a breakthrough strategy.
On the other hand, is there anything really new about the tools and methods of Six Sigma? No, the basic statistical tools such as experimental design and control charts have been around for years. Most Black Belts (BBs) know little more about these tools than what is now being taught in the more modern engineering statistics courses for undergraduates. The DMAIC (define, measure, analyze, improve and control) cycle is an adaptation of the old Shewhart cycle. Getting people to approach problems in a systematic manner is wonderful but not new.
One of the real dangers of Six Sigma is that many BBs believe they know all the practical aspects of experimental design, statistical process control and reliability when they have barely scratched the surface. Still, it is nice to see engineers and others making better use of these important tools. As an academic, I hope as engineers begin to use the tools effectively, they appreciate the need for more sophisticated ones as the situation dictates.
What does it take for Six Sigma to be successful?
There are too many consulting firms that claim expertise in Six Sigma when they barely understand the tools and methods. These firms have jumped on the fad. They specialize in bringing in low hanging fruit, then leave once the problems become more challenging.
Finally, Six Sigma requires the judicious selection of projects and personnel. Projects must have im-pact but also strong potential to succeed. The right people must be assigned and given the necessary time and resources. I have seen Six Sigma initiatives fail because of poor management decisions about which problems to pursue or the composition of the team.
What does the future hold for Six Sigma? Companies will always need to find ways to improve processes and systems. People will always need the appropriate statistical methodologies and structured approaches to make these improvements.
Many companiesfor example, Intelembrace these basic ideas without formal Six Sigma programs. What we call the total package may change, but the essence of Six Sigma will continue for many years.