Lean and Six Sigma DMAIC and DMADV are two fundamentally different but compatible approaches to process improvement. They are both very effective methodologies to be applied when the circumstances call for either one. Lean’s objective is to identify and eliminate waste in all processes, while DMAIC/DMADVs’ objectives are to identify and eliminate variation in a process. While leaders do not have to work the mechanics of the LSS tools, they need considerable savvy in the reading and interpretation of each tool’s outputs. Those who prepare well in this area are able to expect teams to use certain tools to answer certain kinds of questions (thereby driving the proper use of tools). Their understanding helps them to challenge some team findings, to coach teams that may get stuck or off track, and to anticipate the tools and data that will be useful in an upcoming review. Integrating Lean with DMAIC/DMADV is the subject of this chapter and offers the best of both worlds for process improvement practitioners that understand the strengths of each and integrate them seamlessly where applicable.

The identifying and eliminating waste concepts of Lean and the identifying and eliminating variation concepts of DMAIC/DMADV have been difficult for the process improvement community to merge together in a seamless fashion, if at all. In fact, even today there remains poor understanding of how to make both of these excellent tools work in unison. Lean and DMAIC/DMADV show the individuality of each approach, and the complementary nature of these two unique and specific approaches together makes a powerful process improvement philosophy come alive. The goals of Lean can and do use some quantification; however, the Lean philosophy is predominantly qualitative in nature, and this overarching qualitative approach puts a few core beliefs above all activities. In fact, all activities should be traceable back to one of these qualitative business drivers. These are all activities driven by customer demand, establishing continuous flow of products or services to meet these customer needs, and driving waste out of the process until the customer receives perfection as a result of your efforts. The goals of DMAIC/DMADV are rooted in quantitative analysis and the scientific method. In their book Science for All Americans (Oxford Press, New York, 1990), Rutherford and Ahlgren note: “Scientific habits of mind can help people in every walk of life to deal with problems that often involve evidence, quantitative considerations, logical arguments, and uncertainty … involving four key values: curiosity, openness to new ideas, skepticism, and critical thinking. Curiosity means being filled with questions, seeking answers, and verifying how good the answers are. Openness means being discovery-oriented, even if the ideas are at odds to what is currently believed. Skepticism means accepting new ideas only when they are borne out by the evidence and logically consistent. Critical thinking means not being swayed by weak arguments. Collectively these 4 key values represent the foundation for Scientific Thinking.

While the above difficulties are real, they can be overcome by using the DMAIC/DMADV problem-solving process outlined in this application and by helping people overcome the roadblocks, which is the true focus of the science and art of this approach. Because all products, services, and outcomes result from a complex system of interaction of people, equipment, and processes, it is crucial to understand the properties of such systems. Appreciation of the DMADV design and verification process helps us to understand the interdependencies and interrelationships among all of the components of a system, and thereby increases the accuracy of prediction and the impact of recommended changes throughout the system. However, a person can use the methods described in this application without knowing the theory behind them, just as a person can learn to drive a car without knowing how it moves. Dr. Edwards Deming once said that one need not be an expert in any part of scientific thinking in order to understand and apply it.

The goals of Lean DMADV have their roots in Lean Manufacturing, a comprehensive term referring to manufacturing methodologies based on maximizing value and minimizing waste in the manufacturing process. Lean Manufacturing evolved in Japan from its beginning in Ford Motor when Toyota built on Henry Ford’s concepts for the elimination of waste and just-in-time stocking to create the Toyota Production System (TPS) in Japan. Many of the most recognizable phrases, including Kaizen and Kanban, are Japanese terms that have become standard in Lean Manufacturing and in the past 10 years or so have rapidly spread to the service, government, military, and not-for-profit sectors.

The goals for both DMAIC and DMADV are based upon systematic quantitative approaches to process improvement and process design, respectively. The basic structure and goals of each of these approaches is focused on identification and elimination of variation in both process design and process improvement.

The following is a clarification of the DMAIC process:

• Define: Select an appropriate project and define the problem, especially in terms of customer-critical demands.
• Measure: Assemble measurable data about process performance and develop a quantitative problem statement.
• Analyze: Analyze the causes of the problem and verify suspected root cause(s).
• Improve: Identify actions to reduce defects and variation caused by root cause(s) and implement selected actions, while evaluating the measurable improvement (if not evident, return to step 1, Define).
• Control: Control the process to ensure continued, improved performance and determine if improvements can be transferred elsewhere. Identify lessons learned and next steps.

On one hand, DMAIC is a process improvement tool that is used to modify a process that already exists and does not always provide the performance that is desired, and provides a foundation for a systematic and structured examination of any process. On the other hand, DMADV is a process definition and creation tool that outlines and uses a systematic approach to define, create, and execute a new process for a situation where no process currently exists. Although DMAIC and DMADV have some similar characteristics, DMADV holds the upper hand where a completely clean starting point to design is needed, instead of a continuous improvement building upon the existing process/system. DMADV promotes creative and innovative thinking to create the best process possible from the customer standpoint. It allows process designers the freedom to brainstorm with the approach “If I had a genie who gave me three wishes and a magic wand that could create the perfect process, then what would it look like?”

Here is an important point to remember: Use DMAIC to improve processes and use DMADV to design new ones.

No matter how you approach deploying improvement teams in your organization, they will all need to know what is expected of them. That is where having a standard improvement model, such as DMAIC, is extremely helpful. It provides teams with a roadmap. DMAIC is a structured, disciplined, rigorous approach to process improvement consisting of the five phases mentioned, where each phase is linked logically to the previous phase as well as to the next phase.

The worlds of Lean and DMAIC/DMADV (Six Sigma) have been seemingly at odds for many years. This is primarily due to the difficulty of practitioners grappling with the two fundamentally different concepts— identifying and eliminating waste versus identifying and eliminating variation. As different approaches to process improvement, when applied in the proper situation, Lean and DMAIC/DMADV can integrate to form a more powerful tool than either can be standing alone.

Virtually all Lean concepts integrate well with DMAIC and DMADV. Our purpose in this section of the handbook is to focus on special considerations for using the Lean concepts integrated with the DMAIC/DMADV process in any environment, including both methods and tools that are particularly helpful as well as hints on how to model the people side of each phase.

Lean thinking supports two basic disciplines for speeding up the knowledge creation process—short, frequent learning cycles and delayed commitment. Short, frequent learning cycles are the antithesis of thorough front-end planning, but they are the best approach to processes that have the word development in their title. In product development, for example, the typical process is to define requirements, choose a solution, refine the solution, and implement the solution. Although this process is common, it is not the best way to generate knowledge. Conversely, the delayed commitment approach of Toyota is much faster and delivers products of superior quality that consistently outsell the competition. Toyota builds sets of possibilities to satisfy customer needs, and then, through a series of combining and narrowing, the new product emerges. The combining and narrowing process is paced by milestones that define stages of the narrowing process. Milestones are always met, despite the fact that there are no task breakouts or tracking. Decisions are delayed as long as possible, so that they can be based on the maximum amount of information.

However, Lean thinking sometimes has a big blind spot for the most powerful aspect of Six Sigma—its ability to connect business leaders and key project teams in a potent two-way, fact-based dialogue. To see and understand that an exploration of Six Sigma roadmap architecture is needed, Lean tools can be dovetailed nicely into virtually any DMAIC or DMADV project, regardless of the size and scope involved. They can be used to accentuate DMAIC or DMADV concepts and tools, or as some basic stand-alone techniques to produce a vital component of the DMAIC/DMADV project. Table 6.3 illustrates how and where Lean tools can be integrated with DMAIC/DMADV Project Framework.

As demonstrated in Table 6.3, the application of Lean tools and techniques fits neatly into the structured approach of Six Sigma. Whether you are conducting a DMAIC or DMADV project, Lean can play a significant role in either process design or process improvement. Both concepts fit nicely in the tollgate format, and both align with a structured approach, and have at their core the use of root cause analysis (RCA) as a means for driving effective and permanent process improvement.

Groups of Root Cause Analysis Tools

See Figures 6.1 to 6.6.

FIGURE 6.1

DMADV/DFSS approach.

FIGURE 6.2

DMADV: Overview of Define.

FIGURE 6.3

DMADV: Overview of Measure.

FIGURE 6.4

DMADV: Overview of Analyze.

FIGURE 6.5

DMADV: Overview of Design.

FIGURE 6.6

DMADV: Overview of Verify.

Many organizations first initiate their LSS journey with DMAIC problem solving and improvement, which makes sense for the most part as DMAIC brings rapid improvement to existing process problem areas by quickly returning significant savings dollars and cycle time reductions to the bottom line. And because DMAIC projects often point to problem root causes in the design of products or processes, interest in DMADV (or DFSS, as it is sometimes called) often develops as an offshoot in connection with improvement work needing redesign. Thus, LSS business leaders may find themselves struggling to manage two methods or approaches and roadmaps instead of a unified one. However, the good news is that in a world where “innovate and design” are naturally separated from “improvement work,” a two-roadmap system may work just fine.

In many of our client-related engagements, many of which are profiled in this handbook, design is often interwoven with existing products and processes, and improvement often means revisiting the core fundamental design. In those situations, the SSTs, belts, and champions can waste a ton of energy worrying, “Is this a DMAIC or DMADV project, or both?” When an organization starts to feel that too much time is being spent worrying about the distinctions between DMAIC and DMADV (or is it DFSS?), it may be time to move forward and integrate and simplify things. Experienced LSS practitioners may notice that the thought processes have some parallels, especially in the DMAIC Define and Control phases. While it is tempting, and in some cases even possible, to integrate the approaches in new and creative ways, it is best to use some common approaches with an eye toward caution, as effective integration of the roadmaps requires special attention be paid to the subtle ways in which they are different.

Table 6.4 is a major step in guiding a team toward the correct methodology, no matter where on the roadmap the team was when the project’s nature became clear.

The concluding section of this chapter was summarized in Table 6.4, which depicted a synthesis and integrated view of what happens if the DMAIC and DMADV thought processes are distilled to a high enough level that one map might be laid out instead of two. The “Operational Definition” columns showed the various distinctions that might be important to a particular team, depending on whether its current project was DMAIC or DFSS (or somewhere in the middle). The intended takeaway from this view is that DMA is where many of the DMAIC and DMADV distinctions lie. While they can be overlaid, it is important for each project team member to understand as early as possible where they are on the DMAIC-DMADV continuum. Some projects start out “thinking they are DMAIC” only to find (somewhere in D, M, or A) that they are really more DMADV—or vice versa.

All practitioners appreciate that roadmaps are needed to guide the work in Six Sigma, and that there is an understandable need to simplify and integrate when their complexity starts to get in the way. While considering a “branched” and a “parallel” approach to integrating DMAIC and DMADV, SSBBSs must be armed with as much insight as possible before deciding what is best in their particular environment.