Why are most lean six sigma programs off base?
It would be almost an embarrassment in most manufacturing firms today to admit that they do not have a lean, six sigma, or lean six sigma program. It defines the modern company. Yet, most manufacturing firms have been disappointed with the results of these programs.
So what is the problem? While the results of these projects look great on paper, or in the initial implementation, the actual new processes are rarely followed or sustained and revert back to the prior state. And why does this happen?
Most companies that have these programs think that “experts,” certified as “black belts,” doing formal projects in a standard way is the essence of lean six sigma. Unfortunately, in many companies the highly paid “black belts” are not experts in the manufacturing processes they are supposed to be improving, they did not grow up in the plants and rarely fit into the culture. In other words, they are outsiders who fly down by helicopter to analyze the process, make recommendations, develop plans for measurement to control the process, and fly to the next project. In the meantime, the managers who worked their way up through the hierarchy through many years of hard work have to keep production running while supposedly implementing the ideas of these youngsters. Predictably, they do not buy in and do not take ownership.
Six sigma itself has wandered far from its origin, Total Quality Management, adopted by Motorola in the 1980s to close the quality gap with Japanese competitors. It was a serious commitment to working toward six-sigma quality (3.4 defects per million parts) and Motorola got very close. This then morphed at Allied Signal and GE into six sigma as a tool kit to eliminate any type of variation (e.g., productivity, equipment uptime, inventory) with results measured by cost savings. Black belts were anointed process improvers and given aggressive targets of saving many times their salary to justify their high pay. Mostly they were young people who could quickly learn statistics, but lacked the maturity to be leaders of change. So their long presentations of analysis and recommendations rarely led to sustainable implementation.
Now let’s look at lean. At Toyota it evolved over many decades based on experience, reflection, systematic trial and era, and organizational learning. Total Quality Management became a key part of the Toyota Way, adopted in the 1960s, to dramatically improve quality. The underlying philosophy was to develop people with basic tools for understanding the problem and trial countermeasures to learn what will work to bring them closer to challenging improvement targets. Those on the shopfloor managing the processes were responsible for improving the processes. Any “experts” were only available to coach and help with hard problems. The goal was to more closely approach the ideal of one-piece flow, giving customers exactly what they want when they want it without waste, which requires in the literal sense that all sources of variation are eliminated. There were no “experts,” but people who focused more intently on learning about problem solving and process improvement. Their job was to teach others to improve processes themselves. By developing people to work toward perfect processes to satisfy customers Toyota could adapt to a rapidly changing environment and maintain competitiveness.
As lean-six sigma grew in large bureaucratic corporations it took on the culture of those corporations. As an example, I was invited by one food processing company, whose manufacturing leaders had read The Toyota Way, to be their sensei. They were off to a good start with a focus on two key problems - improving equipment uptime, which was terrible, and moving to three sigma quality as they were worse than that. The six-sigma bureaucrats from corporate mandated that they must do these as defined projects each with a clear cost reduction target. It virtually killed the momentum, and I got fired for arguing against the six-sigma mandate.
I have had many similar experiences in companies that view processes as mechanical things that can be fixed with enough statistical analysis, forgetting the central role of the people who work in the processes. I have also worked with companies with a strong, positive team-based culture where black belts do wonderful work facilitating and teaching. So it is not the methodology, it is the philosophy. The end game should be a culture of continuous improvement.
Dr. Jeffrey Liker is professor of industrial and operations engineering at the University of Michigan and author of The Toyota Way. He leads Liker Lean Advisors, LLC and his latest book (with Gary Convis) is The Toyota Way to Lean Leadership.