A student of mine had numerous questions about the various statistics used in Six Sigma. Here is my response to him in an open email:
The questions you are asking regarding “Where do these statistics come from?” require entire courses in statistics to answer. In Lean Six Sigma we take information from a dozen or so statistics courses, project management courses, psychology courses, business courses, mathematics courses, etc. and put it into an action framework that can be used to make fast improvements. We probably present less than 10% of the information you would receive if you sat through all of these courses, but we do so in less than 5% of the time it would take to complete all of these courses. It’s a tradeoff. We make the greatest compromises in the field of statistics. We discuss the use and interpretation of a select subset of statistics, and answer the question “where do these statistics come from?” by saying “they come from computer software.” While most are satisfied with this answer, some find the answer to be most unsatisfying. Judging from your questions, I suspect you are in the latter group.
Two-Way ANOVA Calculations from E-Handbook of Statistics
Assuming you don’t have the time or the desire to take all of the courses relating to the Lean Six Sigma body of knowledge, but still seek answers to the specific statistics you asked about, I recommend the E-Handbook of Statistical Methods. This reference source is free and very comprehensive. It’s easy to search and will give you the answers you seek. For example, I searched on the term sum of squares, which you asked about, and the search returned pages on the half-normal probability plot (your question about fig. 10.26,) 1-way ANOVA (several of your question were about these calculations,) and several other related topics. A search on ss interaction provides answers to your question about the calculation of this intermediate statistic.
Sorry I can’t address all of your questions via email, but perhaps the reference above will start you on your way to answers. I had the same questions when I started learning about quality improvement nearly 45 years ago, and I am still looking for answers to questions today. Have fun!
CEOs report that their innovation efforts are hampered by unsupportive cultures, rigid organizational mindsets, and lack of processes and discipline. Lean Six Sigma addresses all of these issues. When done properly, Lean Six Sigma can be used to supercharge innovation. Find out more by attending this free webinar delivered by Thomas Pyzdek.
Click the link below to reserve your seat for this webinar.
In the past I have argued that Lean Six Sigma has its limits and that care should be taken when applying it to innovation. My recommendation was based on observations that organizations which tried to do this essentially quashed innovation by trying to measure innovation using the kind of metrics used for operational processes. I concluded that the attempt to measure creativity as if it were a process was a misapplication of Lean Six Sigma that practitioners should avoid.
True enough, but not the whole story. The fact is that when I look at what my clients do with Lean Six Sigma, and review projects from students, I can see that they are, in fact, innovating. In Phase I, when companies begin Lean Six Sigma, it is usually viewed as an initiative and the first efforts focus on creating a culture where change is possible, organizing an infrastructure for change, training a cadre of part- and full-time change agents, and pursuing projects chosen to move the organization towards its vision. This sets the stage for innovation. The real transformation here is in the way people in the organization think, specifically:
They are fact and data driven. Opinions are considered the source of hypotheses to be tested, not absolute truth. The change agents have the tools they need to rigorously test these hypotheses.
They are customer focused and they know how to identify the voice of the customer. This gives them insights into customers needs that go well beyond what customers explicitly say their needs are.
They think of organizations as processes as well as functions. They understand that functions exist to serve stakeholders and enable core processes.
They understand variation differently than their untrained counterparts. They know that some variation demands an immediate response, but other variation requires system changes. They know how to tell one type of variation from the other.
They think of results as stemming from systems rather than individuals.
They know that outcomes–both wanted and unwanted–are caused, and they know how to drill down to these causes. I.e., they understand that processes are transfer functions that transform inputs into outputs.
They understand the importance of focusing on the few critical to quality drivers, and how to identify them.
They know how to organize people for change.
By design the time spent as a full-time change agent is limited. Black Belts serve their terms and return to the organization in other roles. As time goes by these Lean Six Sigma change agents begin to change the organization’s DNA. Phase II occurs as the culture change takes hold and the change agents, now in key leadership positions, see the Lean Six Sigma approach as the best way to lead the organization towards its vision. They see that they can create new and innovative ways to serve their customers’ latent needs based on the intimate knowledge of the customer and the insights gained using Lean Six Sigma on a smaller scale. They better understand the organization’s capabilities based on experiences learned during the deployment of the initiative. Lean Six Sigma moves far beyond discrete improvement projects and becomes the framework for leading the organization as a whole towards its vision.
Lean Six Sigma also teaches leaders a new way to lead. Their involvement in defining the organization’s core processes and enabling functions, identifying process owners, finding opportunities for improvement linked to their strategies, defining the drivers of these opportunities, selecting relevant metrics for the drivers, and linking the metrics to activities throughout the organization (including but not limited to Lean Six Sigma projects,) gives them a new way to get things done.
The combination of a new way of thinking, intimate knowledge of the customer, a culture that embraces and expects change, and a powerful new way to lead, makes it possible for the leadership to bring together disparate parts of their organization all focused on a single purpose: wowing the customer. In short, innovation. This is not the aforementioned clumsy and ill-advised attempt to measure the unmeasurable or to “manage the innovation process,” it is an inspired expansion of the scope of Lean Six Sigma from a purely operational improvement tool to a purposeful search for innovative improvement opportunities. It is the application of the core principles of Lean Six Sigma to the problem of creating a resilient organization that not only responds quickly to changing customer needs and competitive pressures, but also improves the human condition by creating products and services never before conceived.
In summary, Lean Six Sigma becomes the springboard for continuous innovation. It’s a natural extension of the idea of continuous improvement.
The United States Army’s Office of Business Transformation is pursuing a 3 year program to improve its operations, and Lean Six Sigma is a big part of it. According to its web page on Lean Six Sigma, the Army has an award-winning, world-class Lean Six Sigma program that it applies as a core capability in its business transformation. The Army is reviewing core business processes to better support its forces, to reduce waste and to improve quality. The ultimate goal is to free human and financial resources for more compelling operational needs. The Army believes the fusion of Lean and Six Sigma improvement methods is required because:
Lean cannot bring a process under statistical control
Six Sigma alone cannot dramatically improve process speed or reduce invested capital
Both enable the reduction of the cost of complexity
The Army’s deployment is one of the largest anywhere. The Army’s Lean Six Sigma program has trained more than 1,450 senior leaders. As of the date of the report on their web site, the Lean Six Sigma community has completed nearly 5,200 projects, and more than 1,900 projects are currently in progress. Completed projects have yielded significant financial and operational benefits at organizations across the Army.
The Army’s use of Lean Six Sigma is part of its effort to transform the Army through the establishment of the Institutional Army Transformation Commission in August 2011. The Secretary of the Army, John M. McHugh, established the Commission in a Memorandumon 15 August 2011. According to the Secretary, “reforming and restructuring the Institutional Army – the Generating Force – is critical to building the Army of the future and supporting the forces of today. It must be as nimble, agile and adaptive as our Operating Force – driven by ideas, innovation and a determination to bring the best services and equipment, training and leaders, medical care and support to our Soldiers, civilians, and their family members.”
I think its safe to say that creating an organization that is nimble, agile, adaptive, driven by ideas, innovation, and a determination to bring the best are all goals that any leader can embrace. I believe that the Army is correct in believing that Lean Six Sigma can help them achieve these goals.
Military logistics operations are centered on providing the best possible service to their customers. Ensuring the best possible service to soldiers downrange is the priority of every logistics leader. One deployed unit is providing their soldiers an opportunity to learn new ways to improve logistic capabilities. The Task Force Resolute command provides a Lean Six Sigma course at the U.S. Forces Afghanistan conference room on Kandahar Airfield, Afghanistan.
“Through Lean Six Sigma, soldiers and leaders will learn how to properly manage time and resources while delivering a top quality product the first time,” said Chief Warrant Officer Jackie Vuorinen, the TF-Resolute safety officer. “This is a program all soldiers can use to save Army resources while providing higher quality products.”
It’s only natural that the Task Force Resolute command use Lean Six Sigma. After all, providing military logistics is a complex process and, like any process, it can be improved. The current best practice for improving complex processes is Lean Six Sigma. Soldiers are being taught the Lean Six Sigma Green Belt body of knowledge. The most fundamental principal taught by the “Green Belt” course is to center the students thinking to several key concepts: define, measure, analyze, improve and control.
The soldier begins by defining a need within their organization centered around quality, cost or timing. The need must be clearly stated through a quantifiable unit such as units shipped, number of products delivered in a sub-standard state or the amount of time it takes to bring a product to the customer. soldiers measure all their statistics through historical data. The data is analyzed and the implications of faults within the organizations system are used to determine methods of improvement. These methods are implemented and used to create a steady improvement in service to the end customer.
Perhaps the effectiveness of the approach is why, according to the DVIDs website story, that students strongly recommend the course to all leaders and soldiers. In truth, this is the standard Lean Six Sigma approach applied in the context of military logistics. Let’s hope that the word spreads.
Due to popular demand we now offer monthly payment plans for all Six Sigma and Lean Six Sigma training. Plans start as low as $116.25 per payment. Our goal is to make top-notch training affordable for everyone.
The Pyzdek Institute has announced that it is giving away a complete Statistics course with registration for any of its Six Sigma or Lean Six Sigma Green Belt or Black Belt training courses. The statistics course, which includes 4 DVDs and two follow-along printed guides, consists of 24 lectures of 30 minutes each. Part 1 (12 lectures) covers all of the subjects commonly included with college introductory statistics course. Part 2 (12 lectures) explores a wide variety of applications of statistical methods.These challenging yet accessible lectures assume no background in mathematics beyond basic algebra. While most introductory college statistics courses stress technical problem solving and plugging data into formulae, this course focuses on the logical foundations and underlying strategies of statistical reasoning, illustrated with plenty of examples. Professor Michael Starbird walks you through the most important equations, but his emphasis is on the role of statistics in daily life, giving you a broad overview of how statistical tools are employed in risk assessment, college admissions, drug testing, fraud investigation, and a host of other applications.
This offer is good only while supplies last. Click here to register or to get additional details.
From time to time I am asked by a prospective student to compare The Pyzdek Institute to a competitor. Below is a typical response from me to one of these inquiries.
Dear Mr. X,
Thank you for your inquiry. Regarding a comparison of our products to those of [Competitor], I make it a policy not to comment directly on any particular competitor. However, regarding the criteria you may wish to use when making a choice between us and any competitor, might I suggest the following:
Did they write The Six Sigma Handbook? The prestige and value of your certification depends on the reputation of the service provider. If you choose The Pyzdek Institute then the author of your training will be the person who wrote the book that has been the standard textbook in the field for 13 years. His name and signature appears on your certificate. Your certification will be recognized and respected without question.
Is the Certification exam included, or is it an extra charge? The fee for Pyzdek Institute training includes the certification exam.
Is the certification project assessment included? The fee for Pyzdek Institute training includes this at no additional cost.
Are they accredited by The International Association for Six Sigma Certification (IASSC) as a training provider? We are.
Do they have provision for ongoing, low cost site access after completing the course? Our Lifetime Learning subscription provides access to our training site to students for a price that is a fraction of our full subscription price.
Do they include a full one-year license to Minitab statistical software? Minitab is the defacto standard software package for Six Sigma. Our price includes a one year license and our training has numerous videos showing how to use it for performing various Six Sigma analyses.
Do they include a full one-year license to Minitab’s Quality Companion project management software? We do.
Is their student forum (assuming they have one) monitored by and responded to by Thomas Pyzdek, well known author and consultant with over 40 years of hands on experience in Operational Excellence?
Do they offer homework assignments which are graded by Master Black Belts? We do.
Do they have hundreds of self-scoring quiz questions covering the entire body of knowledge to help you learn and prepare for certification exams? We do.
These are just a few of the areas where we differ from the typical competitor. Complete details for all our courses are available in our online store. I look forward to seeing you in one of our courses soon.
The Laney p’ Control Chart is an exciting innovation in statistical process control (SPC). The classic control charts for attributes data (p-charts, u-charts, etc.) are based on assumptions about the underlying distribution of their data (binomial or Poisson). Inherent in those assumptions is the further assumption that the “parameter” (mean) of the distribution is constant over time. In real applications, this is not always true (some days it rains and some days it does not). This is especially noticeable when the subgroup sizes are very large. Until now, the solution has been to treat the observations as variables in an individual’s chart. Unfortunately, this produces flat control limits even if the subgroup sizes vary. David B. Laney developed an innovative approach to this situation which has come to be known as the Laney p’ chart (p-prime chart.) It is a universal technique that is applicable whether the parameter is stable or not.
About Your Presenter, David B. Laney
David B. Laney
David B. Laney worked for 33 years at BellSouth as Directory of Statistical Methodology. He is a pioneer at BellSouth in TQM, DOE, and Six Sigma. David’s p-prime chart is an innovation that is being used in a wide variety of areas. It is now included in many statistical applications, such as Minitab and SigmaXL. David is enjoying retirement with his family in the Birmingham, Alabama area.
Date: Wednesday, September 28, 2011
Session #1, 1:00 PM Eastern Time. Click here to register.
Session #2, 7:00 PM Eastern Time. Click here to register.
Update
Click here to view a video recording of David’s webinar.
