Typically, we are skeptical when a new-and-improved approach to quality comes along. This happened when Just-in-Time (JIT) appeared. Some claimed JIT was incompatible with material requirements planning (MRP), but time and common sense proved JIT concepts can be applied to an MRP environment for significant improvement. Skepticism about new quality initiatives has been put to rest many times over.
Many quality initiatives have been introduced through the years. Some have faded away, and some were merged with, or absorbed by, others. JIT evolved and grew into lean. Six sigma started out as a statistical tool and is now a full-blown philosophy.
Today, two popular quality initiatives, lean and six sigma, share many overlapping techniques, and they both offer unique and useful approaches to solving quality problems. Which one is best? The primary focus of lean is to eliminate waste; the primary focus of six sigma is to reduce variation. Can eliminating waste in a process also reduce or eliminate a possible source of variability? Can reducing variability in a process also eliminate waste? The answer to both questions is an unqualified yes. But many companies focus strictly on one approach to quality and exclude others. Managers often feel that diluting limited resources will interfere with the company success.
Let me digress slightly with an observation. When an automobile needs repair, most owners prefer taking it to a shop that has all the right tools and employs trained technicians who know how to properly use the tools. If it were your car and the mechanic's tool set consisted of various hammers, pliers, screwdrivers, and a full set of adjustable wrenches (e.g., crescent wrenches) but only a few sockets and hardly any other tools, how comfortable would you feel? Would you consider taking your car to a better-qualified shop?
The auto repair analogy is only a starting point. Significant improvement to operations typically requires more than just a "repair." It often requires reengineering parts of your organization. A toolbox that contains all the necessary equipment to do the job right--supplied to people with the requisite skills to perform the work--is an absolute requirement for achieving the desired results.
With a limited set of tools (skill sets), there will be problems that can't be properly fixed. Will learning and applying techniques from multiple quality initiatives overwhelm already limited resources? What about the time and resources required for black belt certification in both lean and six sigma? What if you need to solve a problem but don't have the right tool? Try a hammer?
This begs the questions: Does everyone need training? No. Does everyone need at least some education? Yes. Individuals with lean and six sigma skill sets are a necessity. But a few highly trained, educated, and skilled individuals--who are properly deployed--can successfully deliver the necessary education and training at the appropriate time and guide the efforts of others. Eventually, everyone will acquire a sufficient set of knowledge and skills, and some may even become expert in one or more areas.
Because most quality initiatives are justified by their anticipated return on investment, many organizations feel pressured to drive the initiative throughout the entire organization as quickly as possible to achieve the desired results (payback) as soon as possible. This shotgun approach has some serious side effects (in addition to dilution of resources to the point of ineffectiveness). In reality, this approach drives chaos throughout the organization. When there is too much change, or it comes too fast, people will slow it down--or even bring it to a screeching halt--because they can't deal with it. If you've been part of a shotgun approach, you have observed this phenomenon. It's a real impediment to success. This resistance is one of the major reasons quality initiatives seem to take forever to show real bottom-line results and, thus, are often cancelled.
Many organizations use both lean and six sigma tools in their quality quest. Is this combination enough? I've been around a few years (what an understatement!) and have been involved in the quality evolution. When I claim that you need a full set of tools, I mean you need to include the theory of constraints (TOC) tools in your toolbox. TOC has evolved from an operations application (drum-buffer-rope) into a full-blown, top-to-bottom (high-level strategy to low-level tactics) set of "focusing" tools and proven applications solutions. TOC doesn't duplicate lean and six sigma, it complements them by providing strategic focusing for their applications. Their complementary strengths: TOC: strategic focus; lean: eliminate waste; and six sigma: reduce variability.
TOC brings two significant benefits to the table. First, TOC avoids dilution of resources by targeting the few strategic improvements that provide the most significant improvement to system throughput with minimal use of resources. Second, this same strategic targeting limits the scope of change (in contrast to the shotgun approach), which minimizes an important cause of resistance to change.
Be sure to include individuals with TOC knowledge and skill sets in your organization. Most companies that combine TOC, lean, and six sigma have their own name for it. I refer to this combination as "focused lean." But has anyone successfully done it? Absolutely! One good example is the U.S. Navy. Naval Aviation calls it Airspeed.
Are lean, six sigma, and TOC too much? Absolutely not. Keep an open mind for opportunities to fill the gaps in current tool sets. Remember, lean, six sigma, and TOC all evolved into the powerful tool sets they are today, and they continue to evolve. Who knows what exciting tools the future will bring.
But a word of caution: Beware of zealots who feel their approach is the best, and sometimes only, approach. They are resistant to accepting and learning new techniques.
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