This post is the second part of a two part series about revisiting lean manufacturing and six sigma in the 21st century. Before reading this post, I encourage you to read the post immediately below which is part one in the series. In this post I will discuss six sigma and my recommendations for management.
Six Sigma™ as a brand is simply the repackaging of several statistical tools that have been developed over decades; the only difference being the sequence with which they are deployed. The marketing of six sigma over the past fifteen years has been phenomenal. Huge companies like GE and Motorola trumpeted their success with six sigma and the business world scrambled for it. Books were written by the truckload, consultants hired and people trained by the boatload and a huge revolution in improvement was started. At least that's the story that most people want to believe and most consultants and authors sell. There are several problems with this story; I'll highlight two big ones: the deployment and the results.
Six sigma is typically deployed in a company in the following way:
l Hire a consultant to do training
l Train people as follows:
n Upper management - introduction only, maybe two hours.
n Middle management - Champion training, maybe four hours.
n Master Black Belts/Black Belts (MMBs/BBs) - full-blown 6+ weeks of training in all of the details of six sigma, including leading projects and mentoring other "belts".
n Green Belts (GBs) - 2-4 weeks of training, not as involved as MBB/BB but still pretty deep.
n White Belts/Yellow Belts - some exposure, maybe the same as introduction or Champion training but meant for the remainder of the workforce.
l Define some projects (usually done in parallel with the training so that the trainees have a "real-world" application during their learning)
l Track the projects
l Complete the projects and start counting the money
This deployment plan leads to several problems; let's look at some of them.
BBs and MBBs are dedicated full-time to implementing six sigma and leading projects. GBs and Champions are expected to dedicate a certain amount of their existing work time for their projects. This is the first problem with the deployment of six sigma: GBs and Champions are expected to take time to work on six sigma but there is no subsequent increase in overall resources. The thinking is: "they can take 10% of their time and work on six sigma projects" but that translates into an additional half-day of work per week (or more). For someone who is already working in a downsized department this 10% more work can be a deal breaker. Something has to give and it's usually the six sigma project, especially if their manager is interested in something else.
And that's the second problem with the deployment: the Champions do not have the same level of knowledge about six sigma as their GBs (fours hours of training vs. four weeks of training). In the worst case, the manager is unaware of the importance of this activity (due to poor top-down communication) and doggedly assigns the GB to work on other things, like their "real" job. Who can effectively mentor GBs?
The BBs/MBBs can mentor GBs but their main work is leading multiple six sigma projects per year (usually in parallel). They are measured by the number of projects completed and the amount of cost savings that they "produce", not the number of GB hands that they hold. This means that they are more focused on doing their main job and less on mentoring other people.
What does all of this mean? Unlike lean manufacturing, where there may be only one dedicated person and no part-timers, almost everyone is expected to participate in six sigma. Lean likes to have "Kaizen events" where they recruit some people, do an activity and then let the people get back to work. Six sigma, on the other hand, must have a virtual army of specialists available for any and all projects all of the time. This thinking causes the biggest burden of implementation to fall on the GBs and their Champions, already adding to their workload. And when (if) the projects are completed, what are the actual results?
Results of Deployment
Most companies are able to actually complete several six sigma projects; especially if they've hired several top gun BBs/MBBs to support their deployment. They get all of the way through the DMAIC process, get approval from their Champion and close the project. What happens after that? It all falls apart. The "C" at the end of DMAIC stands for "Control". In this phase of six sigma, the improvements made during the project are documented, stabilized and handed over to the owners of the process. Out of all of the phases of six sigma, I think that this one is the weakest (followed closely by the Define phase). I think that it's the weakest because from my own experience, and the experience of other BBs, I know that many projects soon fail after being handed over to the process owners. This may be for several reasons but most of the time the owners don't really understand what the GB/BB did to their process and revert to old methods. This leads to the interesting phenomenon of multiple projects for the same problem. I don't know how many times I've heard "oh, we had a six sigma project on that last year" when discussing some significant manufacturing problem. What is so wrong with a philosophy/method/system that can allow so much effort to simply evaporate within a short time period? Obviously, measuring immediate cost savings or other metrics and then walking away is not the answer.
Recommendations and Conclusion
So what can management do to really make lasting improvement in their company? I have to admit that there are many valuable tools embedded in lean six sigma and the manager who wishes to ignore them in their entirety places his/her company at an extreme competitive disadvantage. It's not the tools themselves that are the problem; it's the mindset that tries to implement them. I think that companies that are truly successful with lean six sigma are simply successful companies in general. Their management had the correct mindset for improvement, lean six sigma just happened to be the vehicle that they used to implement their thinking. And that's the key: the mindset of the management. Is the direction to cut costs or, even worse, pretend to cut costs by playing with numbers? Or is the direction to be competitive in a global marketplace? And how do these lean six sigma tools help with that direction?
I believe that the core lean tools (pull, kanban, jidoka, poka-yoke, SMED, TPM, etc.) should be taught to all of the manufacturing engineers and manufacturing supervisors. The manufacturing engineers are responsible for planning and installing the manufacturing process. Their understanding of lean tools is crucial so that they can set up a production line using the best methods available, from the beginning. Why set up a line, run for a few years and then decide to do a kaizen event to streamline it? Just set it up that way in the first place. The supervisors face the daily challenges of pulling everything together, they have to manage and use the tools given to them from the engineers to create value for the company. Their understanding of lean tools, equal to the engineers, will guarantee that they will properly supervise the manufacturing operation. As for the existing lean group, make them a manufacturing engineer, manufacturing supervisor or manufacturing manager. Take the knowledge that they have and allow them to implement it every day, instead of when there is a kaizen event.
Six sigma also offers a lot of valuable tools that can aid in manufacturing. Like lean, the tools should be trained to a more general audience such as the quality engineers and manufacturing engineers. Don't bother with Define and Control; just teach the core tools in Measure, Analyze and Improve. Make a "six sigma project" out of one of your new product development activities. Just like lean, use the tools to analyze and improve the manufacturing process before it even exists. You have plenty of time and resources, that's what APQP is all about. And as for your existing BBs and MBBs: quality engineers and manufacturing engineers. Their deep knowledge of statistics and analysis will be invaluable in those roles.
In conclusion, you need to embed the core improvement tools of lean six sigma into your company; don't separate them into a special group with colorful job titles and ambiguous responsibilities. Dispense with internal marketing and exhortations for change. Change yourself and lead others by example. And let your competitors chase the end of the lean six sigma rainbow.