DPMO

Question

My question concerns the process performance metric DPMO (defects per million opportunities). I want to use this to quantify a particular supplier’s performance. My question is, is the number of defects referred to in the calculation the number of defects produced by the supplier (in which case it would involve data I don’t have access to), or is it the number of defects experienced by the customer (which is us)? I of course can count the number of defects we receive from the supplier, but if this metric is supposed to be based on the number of defects produced by an organization, I would have no way of knowing how many defects are produced by the supplier’s process, but contained within the supplier’s facility. My hope is to be able to characterize the supplier’s process performance in terms of sigma level.
Answer

The DPMO metric is not usually considered a point estimate of the true percent defective in the lot (either at the supplier or customer site).  It is a relative performance metric used to equate the observed percent defective from a sample to defective units per million opportunities.  If a supplier culls out all the defective units before shipping to you (i.e. perfect inspection system), your internal DPMO would be 0, even if the supplier DPMO is high. If your goal is to characterize the supplier’s process performance in terms of sigma level, you would need their data, as the data you collect internally is just an estimate for the average outgoing quality from the supplier and not their process performance.

Steven Walfish

Six Sigma Statistical Meaning

Reporting, best practices, non-compliance reporting

Question

I need to understand the statement, “Adding a 1.5 sigma shift in the mean results …….”
I’m used to the bell curve and + /- three sigma.
How does the extra +/- three sigma fit in, and what is this about moving the mean?
Does ASQ have a good book that includes this detail in with basic statistics?

Answer

The idea of 6-sigma leading to a process with 3.4 parts per million defective is not a totally statistical statement.  Using the normal distribution, we know that a process that is centered on its mean will have 0.135% of the distribution outside 3 standard deviations on each tail.  That same process would have 0.00000010% outside of 6 sigma, which does not lead to the aforementioned 3.4 million parts per million outside.  Dr. Mikal Harry in 1992 published a book (see chapter 6) entitled Six Sigma Producibility Analysis and Process Characterization, written by Mikel J. Harry and J. Ronald Lawson. In it is one of the only tables showing the standard normal distribution table out to a z value of 6.  Here is where he stated that processes can shift by 1.5 sigma leading to only having 4.5 sigma limits and the 3.4 parts per million outside the “6-sigma” limits.  I would suggest you look at the six sigma division on the ASQ website (http://asq.org/sixsigma) that will help to better explain the rationale for the shift.

Steven Walfish
Secretary, U.S. TAG to ISO/TC 69
ASQ CQE
Principal Statistician
http://statisticaloutsourcingservices.com

Six Sigma Black Belt

Question

I am currently an Executive Chef working that has been taking online classes for Green & Black Belt Six Sigma.  I am about halfway through my Black Belt classes and would like to pursue my certifications.  However, my company does not have a Six Sigma department and seem to be getting no where on working on a Six Sigma project so I could qualify for the Black Belt certification.  Do you have any advice or guidance that could help.

Answer

This is not an uncommon issue with a number of people.  What he should look into is to work as a volunteer at some non-profit organization on a Black Belt improvement project.  These organizations are always looking for help and this is a win-win for both him and the organization.  He will need to talk to them about what Six Sigma is and the type of project he is interested in doing.

Another possibility is to look at his place of work and if there is a part of the job that has to be done but no one likes doing it. If it is a process, then he could follow the DMAIC process and show improvement.  This could also serve as BB project if he can show the time savings was greater than 50%.

Jim

Jim Bossert
SVP Process Design Manger, Process Optimization
Bank of America
ASQ Fellow, CQE, CQA, CMQ/OE, CSSBB, CSSMBB
Fort Worth, TX

SIPOC

ISO 13485, medical devices, medical device manufacturing

Question:

I’m working on a green belt certification and I have a question about SIPOC.  What would be the examples of inputs for hospital test facility?  The supplier is physician and patient is the customer?

Response:

Supplier=doctor

Input= blood sample, urine sample, sample swab

Process =DNA, microbiology, HVLC

Output =test results

Customer =patient

Helpful links:

How to Create a SIPOC Diagram

Quality in Healthcare

Six Sigma Case Studies

Suppliers, supplier management

Q: I would like to browse through detailed Six Sigma Case Studies. I do not mind making a payment for detailed case studies in the fields of manufacturing, services and software.
Kindly direct me to the requisite links please.

A: Thank you for contacting ASQ and the Quality Information Center.  I received your request for case studies on Six Sigma in the fields of manufacturing, services, and software.

“Six Sigma is an organization-wide approach used to achieve breakthrough improvements tied to significant bottom-line results. Unlike previous TQM approaches, Six Sigma specifies exactly how the organization’s managers s hould set up and lead the effort. Key features are the use of data and statistical analysis, highly trained project leaders known as Black Belts and Green Belts, project selection based on estimated bottom-line results, and the dramatic goal of reducing errors to about three per million opportunities” (taken from The Quality Toolbox, 2nd ed. by Nancy R. Tague)

ASQ has over 100 case studies on Six Sigma in our Knowledge Center.  I have listed some case studies below that fit with the fields you are interested in.  I have also made a note of which case studies are open access.

Software case studies:

Optimizing Software Inspections with Statistical Quality Techniques“, Software Quality Professional, Dec. 2003 (open access)

Integrating Improvement Initiatives: Connecting Six Sigma for Software, CMMI, Personal Software Process (PSP), and Team Software Process (TSP)“, Software Quality Professional, Sept. 2003 (open acess)

Identifying Code-Inspection Improvements Using Statistical Black Belt Techniques“, Software Quality Professional, Dec. 2003

Preempting Problems“, Six Sigma Forum Magazine, Feb. 2010 (open access)

Optimizing the Software Life Cycle“, Software Quality Professional, Sept. 2003 (open access)

Six Sigma for Internet Application Development“, Software Quality Professional, Dec. 2001 (open access)

Manufacturing case studies:

Six Sigma Green, Black Belts Help Manufacturer Save Nearly $1.5 Million“, ASQ Case Study, June 2008 (open access)

Pall Corporation: A Profile in “Process Excellence”“, ASQ Case Study, April 2008 (open access)

Siemens VDO Optimizes Processes Using Six Sigma“, ASQ Case Study, Feb. 2007 (open access)

Variability Reduction: A Statistical Engineering Approach to Engage Operations Teams in Process Improvement“, Quality Engineering, April 2012 (open access)

Spinning a Solution“, Six Sigma Forum Magazine, Feb. 2010

Service industry case studies:

Simplify and Unleash: One Bank’s Strategy for Growth Through Six Sigma“, ASQ Case Study, Sept. 2008 (open access)

Streamlined Enrollment Nets Big Results for Healthcare Leader“, ASQ Case Study, Jan. 2009 (open access)

Help Desk Improves Service and Saves Money with Six Sigma“, ASQ Case Study, August 2006 (open access)

Service Provider Improves Client’s Metrics with Six Sigma“, ASQ Case Study, April 2011(open access)

Lean Six Sigma Increases Efficiency for Financial Services Firm“, ASQ Case Study, April 2012 (open access)

I hope that these case studies are helpful.  Please let me know if you have any questions or if you need additional assistance.

Best regards,

ASQ Research Librarian
Milwaukee, WI

Related content:

To obtain more resources about Six Sigma, including information regarding training and certification, please see the ASQ Six Sigma hot topic page.

Six Sigma Standard

DMAIC process

Q: How are the new ISO 13053-1:2011 Quantitative methods in process improvement – Six Sigma – Part 1: DMAIC methodology, and ISO 13053-2:2011 Quantitative methods in process improvement – Six Sigma – Part 2: Tools and techniques standards to be used?

Is it for certifying Green and Black Belts, or what?  Are there plans for “registering companies” to the standard?  Thanks in advance for your response.

A: The scope of ISO 13053-1:2011 is to “recommend the preferred or best practice for each of the stages of the DMAIC methodology used during the execution of a Six Sigma project. It also recommends how Six Sigma projects should be managed and the roles of personnel involved in such projects. It is applicable to organizations using manufacturing processes as well as service and transactional processes.”

Similarly, the scope of ISO 13053-2:2011 is to “describe the tools and techniques to be used at each phase in the DMAIC approach illustrating them through fact sheets.”

There is no plan at this point to develop documents that have for intent, or scope, to certify Six Sigma Belts or to register companies to the standard.

Michele Boulanger
U.S. TAG to ISO/TC 69 Chair, SC7 Expert

Design for Six Sigma

Control chart, data, analysis

Q: I am preparing a short training session for my company on the topic of Design for Six Sigma.  I am interested in looking at some examples of how other companies or organizations have used DFSS.  Is it possible to get case studies from ASQ on this topic?

A: Thank you for contacting ASQ and the Quality Information Center.  Design for Six Sigma (DFSS) can be defined as “robust design that is consistent with the applicable manufacturing processes to assure a fully capable process that will deliver quality products” (from The Quality Improvement Glossary by Donald L. Siebels).

The ASQ Knowledge Center has over 1500 case studies on various topics.  I have listed some case studies below that deal specifically with the topic of Design for Six Sigma at companies/organizations such as Ford, Delphi Electronics, and the University of Miami:

“DFSS Lights the Way”, Six Sigma Forum Magazine, May 2009
Abstract: Delphi Electronics, a global supplier of automotive electronics and safety systems, uses many problem-prevention and solving methods to achieve flawless product launches and reduce variation and waste. When assigned a particularly challenging project, Delphi’s development team quickly determined that the Design for Six Sigma (DFSS) method offered the best opportunity to develop a process that would meet internal and customer requirements. DFSS minimized development costs by guiding the team to use a very efficient experimental strategy. As a result, capital equipment requirements were reduced, customer performance requirements were exceeded, and the team achieved greater than 6 sigma process capability.

“Six Sigma Saves Nearly $1 Billion, Key Customers, and a Company”, Case Study, Sept. 2006
Abstract: Just months before severe business conditions threatened the company’s economic future, Cummins Inc. deployed an all-encompassing Six Sigma program. Using three versions of Six Sigma, (Technology Development for Six Sigma, DMAIC, and Design for Six Sigma) Cummins has saved nearly $1 billion through the completion of nearly 5,000 improvement projects. While Six Sigma is commonly used to improve internal production processes, Cummins extends this quality methodology to every facet of its business and beyond, to both customers and suppliers.

“Design for Six Sigma at Ford”, Six Sigma Forum Magazine, Nov. 2004
Abstract: Design for Six Sigma (DFSS) is a product development approach that complements Six Sigma problem solving methodology. Many companies developed their own DFSS processes before a standard template became available, but all versions share fundamental strategies and tools. Ford Motor Co. developed its program in 1999 with emphases on the training of black belts and the completion of DMAIC projects. Implementation began at Ford’s Powertrain Division, but soon other divisions were launching DFSS as well. Issues with training and execution of projects highlighted assumptions that required reevaluation, including DFSS rationale, project integration, process flexibility, and training. DFSS implementation at Ford showed the challenges to be more cultural and organizational than technical. DFSS at Ford has emerged as an enhancement to the present product development system that reinforces the company’s Six Sigma skill base.

“Designing New Housing at the University of Miami: A ‘‘Six Sigma” DMADV/DFSS Case Study”, Quality Engineering, July 2006
Abstract: The two methods employed in Six Sigma initiatives to attain a high standard of quality are the define-measure-analyze-improve-control (DMAIC) method and the define-measure-analyze-design-verify (DMADV) method. In this case study, the DMADV management model is used to design a new dormitory concept at the University of Miami. Its purpose it to provide a roadmap for conducting a Design for Six Sigma (DFSS) project.

“Design for Six Sigma and Product Portfolio Optimization”, Six Sigma Forum Magazine, Nov. 2007
Abstract: DuPont recently undertook a Six Sigma Project designed to optimize its customer service and keep supply ahead of demand. Run primarily in a design for Six Sigma (DFSS) framework, the project was as much about developing a product portfolio performance analysis process as it was about identifying areas for improvement in the portfolio. The project’s findings were used to help decide which poor performing products could be dropped from the portfolio and to help improve the performance of other products. Overall, the project identified initiatives that when implemented could deliver additional manufacturing capacity needed to improve customer service.

“Combine Quality and Speed to Market”, Six Sigma Forum Magazine, Aug. 2004
Abstract: Samsung Electronics Company recently adopted Six Sigma DMAIC methodology to prevent anticipated problems and gather feedback data for mass production. Market demands required the company to complete a chip redesign project within six months. The main challenge was to adapt the DFSS methodology to a semiconductor process development that typically takes one to two years. Samsung credits its success with the DFSS project to factors including allowing sufficient time, organizing cross functional teams as needed, not being bound by tools, and guaranteeing process robustness and process margin.

“Seizing an Opportunity”, Six Sigma Forum Magazine, Feb. 2009
Abstract: The U.S. Coast Guard applied design for Six Sigma (DFSS) to redesign an operational requirements process that provides the basis for acquisition programs to develop major assets. A cross-functional integrated process team was formed to initiate a Six Sigma project for developing a new requirements process, but they faced challenges when applying Six Sigma to a knowledge process in a headquarters situation. The team modified the DFSS method and tools to fit a long cycle-time knowledge process with few metrics. The Coast Guard’s modification can serve as a model for applying DFSS to similar processes in many organizations.

I hope that you find these case studies helpful.  Please contact the ASQ Quality Information Center if you need additional assistance.

Best regards,

ASQ Research Librarian
Milwaukee, WI

Six Sigma Green Belt Projects

Q: I teach a course called “Statistical Methods of Six Sigma” at an engineering college. I’m preparing students to take the ASQ Certified Six Sigma Green Belt exam if they are interested (it is not a mandatory requirement of my class).

Here’s my question — most of my students already have jobs lined up after graduation. Some of them are going to places where Six Sigma programs are already fully established. I do have one particular student who is expected to implement a Six Sigma program at the company that she is going to. It’s a small company, and they don’t already have a Six Sigma program in place.

If she passes the ASQ Green Belt exam and receives her Six Sigma Green Belt Certification, how does she go about getting a project approved if she’s working for a company that doesn’t already have existing Belts?

A: To ask a Green Belt to implement a Six Sigma program is not only ambitious, but also somewhat risky.  Green Belts have the least amount of experience in Six Sigma. Regardless, what this person should be doing is look at the company and decide what a good first project would be with an executive mentor.  The candidate should be looking at something that is important to the company and has impact to the business.  It should be something that requires some work and is not obvious to just anyone looking at the project.

Q: I think the expert more accurately posed what my real question is: how does a new grad working for a company that doesn’t currently have a Six Sigma Black Belt program find an executive mentor to approve or qualify her project?

I agree that she will need a Black Belt, but who will/can certify her project if there is not an existing Black Belt or Master Black Belt at her place of work?  (It is a small consulting firm for medical hospitals).

A: I recommend that she approach her local ASQ Section and inquire about mentors.

Jim Bossert
SVP Process Design Manger, Process Optimization
Bank of America
ASQ Fellow, CQE, CQA, CMQ/OE, CSSBB, CMBB
Fort Worth, TX

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ASQ Sections and Divisions:

ASQ Sections are locally organized member groups where you can interact with quality professionals in your community. ASQ’s Forums and Divisions are topic or industry focused communities that are not based in a specific geographic area.

Membership to a section and division is an ASQ member benefit.

Lean Six Sigma

Reporting, best practices, non-compliance reporting

Q: Can you explain what Lean Six Sigma is to me?  I’ve heard of both lean and Six Sigma as individual concepts, but I’m not quite sure I understand the term Lean Six Sigma.

A: The following concise definition is taken from the book The Certified Six Sigma Black Belt Handbook, 2nd ed. by T.M. Kubiak and Donald W. Benbow (ASQ Quality Press, 2009): “Lean-Six Sigma is a fact-based, data-driven philosophy of improvement that values defect prevention over defect detection. It drives customer satisfaction and bottom-line results by reducing variation, waste, and cycle time, while promoting the use of work standardization and flow, thereby creating a competitive advantage. It applies anywhere variation and waste exist, and every employee should be involved.”

The ASQ Knowledge Center has over 700 resources regarding Lean Six Sigma.  For a more in-depth look at Lean Six Sigma, you may want to consult these resources:

Books:

The Certified Six Sigma Master Black Belt Handbook
ASQ Quality Press, 2012

The Certified Six Sigma Black Belt Handbook, 2nd ed.
ASQ Quality Press, 2009

The Executive Guide to Understanding and Implementing Lean Six Sigma
ASQ Quality Press, 2007

Lean Six Sigma Project Execution Guide
Citius Publishing, Inc., 2011

Lean Six Sigma Demystified, 2nd Ed.
McGraw-Hill, 2011

Articles & Case Studies:

“Lean Six Sigma’s Evolution: Integrated method uses different deployment models”
Quality Progress, January 2008

A history of Lean and Six Sigma deployment, from Motorola’s first Six Sigma adoption in 1987 to the development of four major deployment models, with guidance on which might be right for your organization.

“Stock Options”
Six Sigma Forum Magazine, August 2010

Until recently, lean and Six Sigma philosophies were considered distinct and separate improvement methods, but today many organizations are integrating the two and adding other improvement systems as well. A lean Six Sigma (LSS) approach to inventory control and planning can provide a competitive edge by working with customers to develop solutions to problems. The successful application of the LSS approach to inventory management by a Taiwanese supplier of gardening and building materials illustrates the advantages of the method.

“Better Together”
Six Sigma Forum Magazine, May 2009

Continuous improvement professionals often debate the virtues of a lean or a Six Sigma approach, but the benefits of bringing the two together are significant. Six Sigma can improve the effectiveness of a system by optimizing it and reducing process variability, whereas lean can improve the efficiency of that system by stabilizing work in process, reducing inventory, and eliminating waste. A simple group demonstration allows participants to gain an understanding of the advantages offered by lean and Six Sigma when they work together.

“Weapon Against Waste”
Six Sigma Forum Magazine, February 2012

Lean Six Sigma (LSS) is U.S. Army’s weapon of choice for fighting off process inefficiencies that result in wasted time, money and material. Since 2009, the army’s LSS projects have resulted in a combined savings of $96.6 million.

“Improving Productivity Through Lean Six Sigma Warehouse Design”
Case Study, February 2009

As a key customer’s order volume rapidly increased, New Breed Logistics struggled to keep pace. An improvement team worked collaboratively with internal and external stakeholders to find solutions to meet the challenges of both current and future customers. The team applied Lean Six Sigma methodology by employing quality tools such as value stream mapping, PICK charts, and the 5 Whys to increase product flow and meet customers’ packaging requirements.

“Streamlined Enrollment Nets Big Results from Healthcare Leader”
Case Study, January 2009

Demonstrating that big results are possible in just a short time, Kaiser Permanente Colorado’s Medicaid Enrollment Project Team used Lean Six Sigma methodology to evaluate and improve the organization’s Medicaid enrollment processes.

Webcast:

A Webcast Overview of the Seven Lean Six Sigma Tools
August 2010

This webcast provides an overview of the seven common Lean Six Sigma tools: 5S System, Seven Wastes, Value Stream Mapping, Kaizen, Flow, Visual Work Place, and Voice of the Customer.

You can further search ASQ’s resources on Lean Six Sigma by visiting the ASQ Knowledge Center.

Best regards,

ASQ Research Librarian
Milwaukee, WI