23. Concluding Remarks and the Future of Six Sigma – Six Sigma for Business Excellence: Approach, Tools and Applications


Concluding Remarks and the Future of Six Sigma

Six Sigma for Cultural Change

Six Sigma projects are chosen carefully and should have sizeable financial benefits. This is appropriate when a project is being undertaken. But once Six Sigma black belts complete their tenure as belts, which takes them about two years, they take up a new responsibility in business. Most belts take up positions a level or two above their earlier positions. It is their responsibility to continue the philosophy and application of everything that they learned. Others in the organization are likely to follow these leaders and spread the message further.

Here is a story I once heard. The great boxer Mohammad Ali was once beaten by a guy of ordinary physique and strength. Ali's friend asked him why he did not use one of his punches which made him the world boxing champion. Ali replied that he was not being paid for this punch!

If we extend this analogy to Six Sigma, the belts will not apply the tools to anything outside the project because the savings are not tangible. The financial benefits of Six Sigma should not become a barrier in taking up important and strategic projects.

Is the Six Sigma philosophy new? If we want to answer this question, we should try to remember the contribution of many great quality gurus in the quality journey. The principles and tools of Six Sigma are not new. Shewhart did not propose the theory of control charts for implementing Six Sigma projects. Fisher did not invent the statistical procedures to support the Six Sigma approach. Similarly, Crosby's zero defect approach was meant to be implemented across the organization in everything that is being done in the company. Shingo's poka yoke (mistake-proofing) was to prevent defects from being produced. He did not call it Six Sigma. Thus the philosophies and concepts were meant for application wherever appropriate, generally across the company. As a matter of fact, if there had been a “copyright” on some of these concepts, Six Sigma would not have taken its form the way we see it. As such, the phrase “Six Sigma” came into existence much later during the 1980s when Bill Smith coined it and Bob Galvin, the CEO of Motorola, embraced it.

If the philosophy and tools are not new, why should we restrict its application to identified projects only? We should constantly look for potential applications to improve the performance for the sake of our customers. Most Six Sigma training programs require belts to take up a project before the start of the program. This is an excellent idea as it forces the belts to apply the concepts and tools immediately after the training and before the tools are forgotten. However, this does not mean that the concepts and tools are useful only for projects where benefits are quantified in financial terms. I have observed in the past that after barely completing one project, the belts neither undertake the next project, nor do they apply the powerful tools in their regular work. If we know for sure that there is an urgent need to improve and we see an application of some of the tools, we need not wait till the project charter is signed off and approved. Most organizations implementing Six Sigma require the approval of sponsors, master black belts (MBB), champions and financial controllers. The approval cycle time may be a few days. There is also some cost associated with the approval process. Bureaucracy has silently encroached Six Sigma! There are many opportunities where waiting even for a week may not be acceptable. I have personally handled projects which were completed in less than one week or sometimes a fortnight. I will rate such projects very high whether these are called Six Sigma or not. The belts should not stop applying the concepts and tools just because their projects are over. Six Sigma belts are considered as future leaders of the organization and they usually take up important business positions after completion of their tenures as black belts. Thus they must inculcate a sense of the fact-based decision making into their work culture.

Till the 1980s, most of the statistical tools were primarily used by statisticians. These required a lot of manual calculations. Few DOS-based software programs were available but these were not very user-friendly and required statisticians to manage the input and interpret the output. With user-friendly software applications and a large number of managers, engineers and professionals trained for Six Sigma, many of the tools could be applied by these trained professionals. This is one of the major revolutions that Six Sigma has brought. If the tools can be easily applied, these must be used. If the trained belts do not use these tools, there will be waste of skills learnt and a bunch of “underutilized people”.

Some examples to illustrate cultural change are given here. These are not Six Sigma projects but part of regular work of engineers and managers.

  • We want to establish process parameters for a process. We can map the process and optimize the parameters using designed experiments.
  • Historical data of a process is available for process parameters and performance. We can analyze the data using regression or other tools to find opportunities for improving the process.
  • Parts for a new source are being tested for comparing the wear with parts from the current source. The new source may save a lot of money for the company. The decision can be taken using hypothesis tests ensuring adequate power in the test.
  • We want to confirm whether corrective action is effective or not. We can compare the performance before and after the corrective action.
  • Performance data of various call centers is available. We may use some of the graphical and statistical tools to compare the performance to conclude whether some centers are better or worse.
  • The sales team wants to develop a forecasting model based on the past data.
  • Marketing wants to find out which advertisement results in higher sales.
  • The service manager wants to assess the dealers’ service performance in terms of service time for various types of service calls.

The tools can be used in many applications other than businesses. To illustrate the point, a control chart has been used (see Figure 23.1) to show the Indian cricket team's winning performance in one-day cricket matches till 2007. The p-chart has varying sample sizes and, therefore, control limits are also different for every point.

We can see that the control limits are wider in the initial years where the number of matches (sample sizes) are low. The performance was unusually low in 1997. Another example is the comparison of the performance of two great batsmen, Sachin Tendulkar of India and Brian Lara of West Indies against Australia (see Figure 23.2).



Figure 23.1 Control chart (p-chart) for winning proportion of Indian team every year



Figure 23.2 Individual value plot of comparison



Figure 23.3 Scatter plot of the scores of students
(Reproduced with permission from Institute of Quality and Reliability)


An excellent example comes from a survey that my company conducted in 2008 for the performance of students in Higher Secondary Certificate (HSC) examination and the Combined Engineering Entrance Test (CET). This was to assess whether CET is required or has become redundant. Figure 23.3 shows a scatter plot of HSC PCM score vs MH CET total, which is interesting.

When I showed this chart to professors of a reputed engineering college in India, all of them unanimously said that the combined entrance test is redundant and not necessary. But Indian coaching classes earn millions of rupees through coaching for CET in most states of India. Mr. Kapil Sibal, education minister of India, has announced a policy that the state entrance exams will be abolished and combined all India entrance exams will be conducted from 2013 for admissions to engineering and medical colleges.

It is high time organizations and Six Sigma professionals realized that the Six Sigma approach does not end when the projects are completed. We must change the way in which data is managed and analyzed and decisions are made. Else, the most intense Six Sigma training could be a waste of “talent”.

Six Sigma Without Calling it Six Sigma

I am tempted to submit a case study here. I did not include this in the chapter on case studies because this is not a formal Six Sigma project; it is more than a project! The case study is about the dedication and passionate application of improvement philosophy and tools to improve the well being of some of the most backward tribes in India.

In 1986, Dr Abhay and Dr Rani Bang set up a non-government organization which they named ‘Society for Action and Research in Community Health’ or ‘SEARCH’. Both Abhay and Rani were gold medalists and had obtained post-graduate degrees in public health from John Hopkins University. They were inspired by the Gandhian principles. The primary mission of SEARCH was to improve the overall health of the extremely backward and poor tribes in and around Gadchiroli situated in the central part of India. Due to the absence of any reliable data on health in the region, they spent sufficient time in understanding the needs and priorities of the tribes (Voice of the Customer).

By conducting the first ever study on women's reproductive health in two villages in Gadchiroli and publishing her findings in the Lancet, Dr Rani Bang first brought to the notice of the world the fact that rural women had a large hidden burden of gynecological diseases. She subsequently trained the traditional birth attendants (TBAs) in villages to make them village-level health workers. With convincing evidence to back her, she advocated the need for a comprehensive reproductive health-care package for rural women in India.

Based on their surveys and interactions with people, SEARCH decided to prioritize reducing the infant mortality rates. They collected data on infant mortalities and concluded that pneumonia was the largest contributor, causing more than 25 percent deaths in children below 5 years of age. This was a fact-based revelation, contrary to the then published information.

With many constraints on account of poverty and illiteracy of people, a very innovative but profound and systematic approach was used to solve this problem. A number of village health workers (VHWs) and TBAs were trained to diagnose and treat pneumonia. Four messages were given to them as guidelines:

  • Cough in a child without fast breathing or difficulty in breathing can be treated at home.
  • Fast breathing or difficulty in breathing may indicate pneumonia and would require treatment.
  • Treatment is available in the villages with the medic.
  • An effective medicine called ‘kotra’ (for co-trimoxazole) is available for free.

To spread awareness, two health carnivals or jatras were held in the area.

It was soon realized that the visual method used by illiterate TBAs to diagnose pneumonia resulted in wrong diagnosis in 41 percent of the cases with borderline respiratory rates. This was a major opportunity for improving the “measurement System”. A simple device named breath counter was designed and the TBAs were trained to diagnose pneumonia in children using this instrument (Bang 1992). The breath counter was a simple, cheap and an effective aid which could be used even by illiterate TBAs who could not count to more than 12. This device used an abacus with two rows of beads for various age groups of children. Five beads were white and one was red. It had a sand clock of one-minute duration. The method was simple: one white bead was moved with every 10 breaths. If a red bead was required, pneumonia was diagnosed. The correctness of diagnosis improved significantly to 82 percent with the use of the breath counter.

If diagnosed positive, children with pneumonia were treated with proper medicine. After the first year of intervention, the infant mortality rate of children of age less than 5 years due to pneumonia dropped to about 8.1 per 1000 children as compared to 17.5 in the “control” areas where remedial actions were not initiated. The original paper provides the details of the hypothesis tests and the adequacy of the sample size.

Dr Abhay and Dr Rani Bang, along with their colleagues, have developed a model for a village health-care program which is now being recognized nationally and internationally. They have demonstrated how pneumonia in children can be managed in villages and also how neo-natal care can be provided at the village level. Their innovative approach of empowering the village women to take care of their community's health has reduced the infant mortality rate in their work area from 121 to 30, which is the best indicator of their work. This model has been successfully replicated by NGOs and by the Indian Council of Medical Research of the Government of India in five states. This has recently been incorporated in the 11th Five Year Plan of India.

Dr Abhay Bang has served as a consultant to both the World Health Organization and the Government of India, for which he is currently a member of the National Commission on Population. He also serves on the advisory board for the global saving newborn lives initiative. He is the recipient of several awards, including Maharashtra's highest honour, the Maharashtra Bhushan, and the prestigious Mahatma Gandhi Award.

Dr Rani Bang has been awarded the national award for Women's Development through Application of Science and Technology in recognition of her outstanding and pioneering contribution for the past two and a half decades on improving women's health in rural India through an innovative and powerful approach of research with the people and for the people. She has spearheaded the development of a comprehensive village health-care program which has now become a nationally and internationally acclaimed model. This innovative approach of empowering rural women to take care of their community's health has reduced the infant mortality in Gadchiroli, Maharashtra, by over 75 percent. The award was conferred upon her in New Delhi by the President of India, Smt. Pratibha Patil, at the national conference on Showcasing Cutting-Edge Science and Technology by Women.

The Future of Six Sigma

As I was writing this chapter, I noticed a survey by Quality Progress, the monthly magazine published by ASQ. The question was: Is Six Sigma on the way out? After I voted ‘no’, I saw the interim results of the survey. About 51 percent said no and 32 percent said yes. The remaining 17 percent said they cannot predict. There is also an interesting article “Critical Stage”, in Quality Progress of September 2009 authored by A. H. ‘Jack’ West. The article uses interesting data to draw conclusions about the future of Six Sigma. Some facts presented in the article are:

  1. The number of persons taking black belt certification examination (ASQ) is increasing every year
  2. The number of papers on Lean Six Sigma (LSS) in ASQ conferences peaked in 2002 and then dropped between 2002 and 2005. From 2005 till date, it is approximately stable.
  3. The number of articles published on LSS peaked during 2002–2003 and since then it is tapering down.
  4. A comparison of the three companies—Motorola, GE and the Bank of America—with Standard and Poor's (S&P) 500 index shows that these three companies have not outperformed the market.

The following can be considered as some of the strengths of the Six Sigma approach:

  • It is a project-based approach.
  • Projects are directly linked to financial savings and strategic objectives.
  • Comprehensive training is given to belts with a strong foundation in the use of statistical tools and data-based approach.
  • Projects are completed in 4 to 6 months’ time and results are visible immediately.
  • The Six Sigma vision is near-perfection. This provides the motivation to do better.
  • Belts get trained on many improvement and decision-making tools and get ready to take on greater responsibilities.

In criticism of Six Sigma:

  • A large number of small problems may not get included and can remain open.
  • Six Sigma tools are difficult to understand and training is only given to a chosen few. Many employees feel left out.
  • Complex strategic projects of long duration may not happen.
  • There are projects where financial benefit is difficult to quantify in short term. These get excluded.
  • Six Sigma implementation is expensive.
  • Sustainability is questionable.

To overcome the consequences of the criticism, many actions can be taken. Here are some that can be considered:

  • Do not consider Six Sigma in isolation of other approaches. Keep in mind that Kaizen, Lean and TPM can be complementary to each other.
  • Provide a certain level of training to all employees; involve them in teams and recognize their effort so that they don't feel left out.
  • Prioritize projects that make structural improvements and address systemic weaknesses rather than projects with one-time gains.
  • Create a robust mechanism to select and close projects. Do not allow closure of projects with “temporary” fixes and superficial actions.
  • Do not use the “number of projects” as targets. This can lead to deterioration in project quality. It can also lead to a tendency of every improvement getting named as a Six Sigma project.

I believe that, fundamentally, the success of Six Sigma or any other improvement approach depends heavily on the commitment and drive of the top management. If this commitment is strong, then Six Sigma is a good approach to effectively achieve excellence in business.

Six Sigma will possibly get integrated with other approaches in future. It is already deployed with Lean under the name Lean Six Sigma (LSS), as discussed in Chapter 19. Another possible direction is combining it with a balanced scorecard. The scorecard is used as a top-level radar to ensure that the efforts are in the right direction. It is also likely that some companies will choose to link business excellence models with Six Sigma. The excellence criteria would enable them to identify gaps whereas Six Sigma will be the approach adopted to reduce the gaps.

Process Six Sigma in its current form does not adequately address improvement in reliability. This is one of the reasons why end users do not experience the desired level of the positive impact of Six Sigma. They feel that a product from a Six Sigma company will never fail. However, this is far from the truth. The DFSS roadmap addresses the reliability issue to some extent. I believe that sooner or later, this need will force Six Sigma practitioners to widen the scope of the approach to include reliability improvement tools.

Quality is a journey with no terminus! The journey will continue with the blend of a roadmap and tools which have remained quite stable from the days of Shewhart, Fisher, Deming and Juran. After all, what is so important about the name of the approach?


Bang, Abhay (1992). “Breath Counter: A New Devise for Household Diagnosis of Pneumonia”. The Indian Journal of Paediatrics, Vol. 59.

Conti, Tito, Yoshio Kondo, and Gregory H. Watson (2003). Quality into the 21st Century: Perspectives on Quality and Competitiveness for Sustained Performance. Milwaukee, WI: American Society for Quality.


West, A. H., ‘“Jack’” (2009). “Critical Stage of Six Sigma”. Quality Progress, September. Milwaukee, WI: American Society for Quality.

World Health Organization (1994). Bulletin of the World Health Organization. Geneva.