Six Sigma 101
This defect-measurement
and quality-improvement tool
was designed to make businesses
as successful as possible. Its ultimate
objective: Deliver worldclass performance,
reliability and value to the customer.
BY SUBRAMANIAM MANIVANNAN
ix Sigma is a metric for measuring America s most gifted CEOs, such as goal in mind: make their businesses as
defects and improving quality, and Motorola s Bob Galvin, Allied Signal s successful as possible. Once they were
Sa methodology to reduce defect lev- Larry Bossidy and General Electric s convinced that tools and techniques of
els below 3.4 defects per million oppor- Jack Welch. These people had a single Six Sigma could help them do this, they
tunities (DPMO). It provides a method
to manage process variations that cause
Total Quality Management versus Six Sigma
defects defined as unacceptable devi-
Total Quality Management Six Sigma
ation from the mean or target and
An infrastructure of dedicated change agents focusing
systematically work toward managing
A functional specialty within
on cross-functional value-delivery streams rather than
variation to eliminate those defects. the organization
functional division of labor
The ultimate objective of Six Sigma is to
Focuses on strategic goals and applies them to cost,
deliver worldclass performance, relia- Focuses on quality
schedule and other key business metrics
bility and value to the end customer.
Driven by tangible benefit for a major stockholder
Motivated by quality idealism
group (customers, shareholders and employees)
Advantages over TQM
In some aspects, total quality man-
Loosely monitors progress Ensures that the investment produces the
agement (TQM) and Six Sigma share
toward goals expected return
the same philosophy of how to assist
People are engaged in routine duties Slack resources are created to change key business
organizations in improving quality.
(planning, improvement and control) processes and the organization itself
They both emphasize the importance of
top-management support and leader- Emphasizes problem solving Emphasizes breakthrough rates of improvement
ship. And both approaches make clear
Focuses on standard performance, Focuses on world-class performance,
that continuous quality improvement is
e.g. ISO 9000 e.g. 3.4-ppm error rate
critical to long-term business success.
Quality is a permanent full-time job
However, why has the popularity of
Six Sigma job is temporary, and career path
with a career path in the quality
TQM waned while Six Sigma s popu-
leads elsewhere
profession
larity continues to grow?
Provides a vast set of tools and Provides a selected subset of tools and techniques
Unlike TQM, Six Sigma was not devel-
techniques with no clear-cut and a clearly defined framework for using them to
oped by technicians who only dabbled
framework for using them effectively achieve results
in management and, therefore, pro-
duced only broad guidelines for man- Goals are developed by the quality Goals flow down from customers and senior
department based on quality criteria and leadership s strategic objectives; goals and metrics
agement to follow. The Six Sigma way of
the assumption that what is good for are reviewed at the enterprise level to assure
implementation was created by some of
quality is good for the organization that local sub-optimization does not occur
Subramaniam Manivannan is quality Developed by technical personnel Developed by CEOs
coach/assessor-PTO quality in the man-
Focuses on long-term results, Looks for a mix of short-term and long-term
ufacturing process/product support depart-
expected payoff is not well-defined results as dictated by business demands
ment at Ford Motor Co., Dearborn, MI.
42 METALFORMING / OCTOBER 2006 www. met al f or mi ngmagazi ne. com
developed a framework to make it happen. requires creativity. And the greatest According to a recent benchmarking
The differences between TQM and enemy of creativity is hierarchy. report, successful Six Sigma initiatives
Six Sigma are summarized in the Total Because hierarchy in a traditional firm share three characteristics:
Quality Management versus Six Sigma controls all of the resources material " Implementation teams led by sen-
table. and human an individual employee must ior executives
obtain permission from someone to " Well-organized training programs
How to Make use any resource. If the resources required " Ability to create a corporate culture
Six Sigma Work to pursue a creative idea are controlled that values objective performance meas-
Several companies have attempted to by several positions in the hierarchy, urement.
implement Six Sigma, and the results the employee must get permission from Organizations attempting to imple-
proved disappointing. Why? each for things to move ahead. ment Six Sigma initiatives without
" Maybe they didn t really need Six
Sigma in their company or department.
" Perhaps the wrong person was cho-
sen as the Black Belt.
" Maybe someone at the top didn t
get behind the initiative.
" Perhaps key team members didn t
understand Six Sigma, and, therefore,
could not implement it effectively.
Company-wide understanding of
the Six Sigma process is required for
company-wide buy-in and, ultimately,
company-wide success. In general, proj-
ects are tied to business goals that can be
found in the Balanced Scorecard or
other system, which allows a company
to make sure their efforts are directed to
critical areas.
Six Sigma betters an organization at
all levels. At the highest level, this
involves moving the entire organiza-
tion from a Three or Four Sigma busi-
ness process to a Six Sigma process,
which requires reducing defects by a
factor of more than 20,000, completely
transforming the organization s culture.
What does that mean? Consider 3.8
Sigma, which reflects a process that is
 99 percent good. This may mean
20,000 lost articles of mail per hour,
unsafe drinking water for almost 15 min.
per day, 5000 incorrect surgical opera-
tions per week and two short or long
landings at most major airports each
day. Six Sigma, reflecting a process that
is  99.99966 percent good, means seven
lost articles of mail per hour, unsafe
drinking water for 1 min. every seven
months, 1.7 incorrect surgical opera-
tions per week and one short or long
airplane landing every five years. Quite
a difference.
But Six Sigma can t be accomplished
simply by tweaking the process it
www. met al f or mi ngmagazi ne. com 43
Six Sigma
addressing these three areas are far less used by Black Belts and Green belts, Six Sigma s impressive bottom-line
likely to reap the rewards enjoyed by including up-to-date computer tech- results normally flow from Six Sigma
successful Six Sigma programs. Key nology, are highly advanced. But the projects.
drivers for Six Sigma success include tools are applied within a simple per- Properly defined Six Sigma projects
winning executive support for Six Sigma formance-improvement framework meet certain criteria:
initiatives, linking Six Sigma with suc- known as Define-Measure-Analyze- " Have clearly defined deliverables;
cession planning, defining critical objec- Improve-Control (DMAIC). DMAIC " Are approved by management;
tives for the Six Sigma program and is analogous to the older TQM model " Are not so large that they re unman-
demonstrating the impact of quality known as the Deming Cycle: Plan-Do- ageable nor so small that they re unim-
initiatives on customers. Study-Act. portant or uninteresting;
DMAIC is used almost universally to " Relate directly to the organization s
Six Sigma Simplified guide Six Sigma process-improvement mission.
Six Sigma s magic doesn t lie in sta- projects.Although truly dramatic improve-
tistical or high-tech razzle-dazzle but in ment in quality requires transforming The DMAIC Process Defined
tried-and-true methods that have been the management philosophy and organ- D = Define
around for decades. In fact, Six Sigma ization culture, the fact is that actual Define is the first phase of the
discards a great deal of the complexity projects must be undertaken sooner or DMAIC model. The purpose of the
that characterizes TQM. By one expert s later to make things happen. Projects are Define phase is to refine the project
count, there are more than 400 TQM the means through which processes are team s understanding of the problem to
tools and techniques. Six Sigma takes a systematically changed the bridge be addressed and define customer
handful of these methods and trains a between the planning and the doing. expectations for the process.
small cadre of inhouse technical leaders, However, DMAIC is not a method of Elements of this phase include a spe-
known as a Six Sigma Black Belts or planning projects. Project planning is a cific statement of the problem being
Green Belts, to a high level of profi- subject in its own right. Although proj- addressed, descriptive statements out-
ciency in the application of these tech- ects and plans are closely related, they lining locations and/or occurrences of
niques. To be sure, some of the methods also differ in many respects. problematic events, and an initial
44 METALFORMING / OCTOBER 2006 www. met al f or mi ngmagazi ne. com
Six Sigma
80-percent target. Then the team must
The DMAIC Process
clearly define and quantify the problem,
identify the potential metrics and meas-
urement sources, and identify the neg-
ative attributes and current perform-
ance, and their relationships to the
customer.
Questions to ask in this phase include:
Who is my customer?
What matters, what is critical to
quality?
What is the scope?
What defect am I trying to reduce?
By how much, what is the goal?
What is the current cost of the defects?
M = Measure
The Measure phase establishes tech-
statement describing the scope of the The team must develop a problem niques for collecting data about the
problem. statement, a specific statement of the current performance and how well it is
In this phase, the project team defines problem being addressed. It is extreme- meeting customer requirements. Upon
what is needed for a successful Six ly important to identify the right prob- completion of this phase, the project
Sigma project. Defining includes iden- lem.  Our first run is too low is too team will have a data-collection plan,
tifying customers (internal/external), general not a good problem identifi- valid measurement system that ensures
identifying customers needs, and deter- er. A better one:  In June, Zone A s aver- accuracy and consistency in data col-
mining the project s scope and goals. age first run of 60 percent was below our lection, baseline frequency for defects
46 METALFORMING / OCTOBER 2006 www. met al f or mi ngmagazi ne. com
Six Sigma
and sufficient data for problem analysis.
How Ford Benefited from Six Sigma
This phase prompts the following
Ford Motor Co. s Dearborn (MI) Engine and Fuel Tank Plant produces 1200 engines daily 2.0-liter
questions:
for the Focus and 2.3-liter for the Ranger and 1.2 million fuel tanks annually for a variety of
What is my process?
vehicles. Nearly 1000 workers ply their trade in the 2.3-million-sq.-ft. plant that stakes a claim as
Which outputs most affect quality? the world s largest single manufacturer of steel fuel tanks.
With management support of its consumer-driven Six Sigma program, the plant has achieved
Which inputs seem most to affect
measurable results thus far in 2006. To start, all upper management underwent intensive four-
outputs?
week Six Sigma Black Belt training, followed by the setting of annual Six Sigma cost-saving
Is my ability to measure/detect good
objectives.
enough?
For 2006, the plant set
How is my process doing today? an objective of $6 million
in savings for Black Belt
How good could my process be if
projects and $2.9 million
everything were running smoothly?
for Green Belt projects.
What s the best that my process was
Through June, the Black
designed to do?
Belt projects have achieved
61 percent of the cost-
saving goal, with Green
A = Analyze
Belt projects achieving
The Analyze phase allows the project
28 percent. One Black Belt
team to target improvement opportu-
project focused on
nities by taking a closer look at the data.
production of engine cam
Through this phase, the team will deter- shafts, where two specific
plant operations were each
mine why, when and where defects
saddled with a 17-percent
occur; select the appropriate graphical
scrap rate. Working with
analysis tools and apply them to the
suppliers and closely examining grinding operations, as well as adopting new tooling and gauging,
data collected; and target a set of poten-
one operation was able to cut its scrap rate to 2 percent. The other has seen its scrap rate cut to
tial improvements for action in the fol- 14 percent with plant Black Belt project champions still addressing the issue.
lowing Improve phase. After analyzing,
48 METALFORMING / OCTOBER 2006 www. met al f or mi ngmagazi ne. com
the team can deliver a detailed process ing plan to document the changes and
map, a refined problem statement and improvements.
WANT
estimates of opportunities for defects. Questions to ask yourself in the Con-
MORE?
Questions to ask in the Analyze trol phase include:
Learn more about quality improve-
phase include: Once I ve reduced the defects, how
ment for metalformers by visiting
Which inputs most affect quality, do the functional team and I keep them
www.metalformingmagazine.com
and to what extent? there?
If I change an input, do I really What do I set up to keep perform- and clicking on the Testing &
change the output? ance satisfactory even when things
Inspection/Quality Control
How many observations do I need to change (people, technology and cus-
Enterprise Zone.
draw conclusions? tomers)? MF
What level of confidence do I have
regarding my conclusions?
I = Improve
In the Improve phase, the project
team develops, implements and vali-
dates improvement alternatives that
will fix the process. This consists of
brainstorming to generate improve-
ment alternatives, testing proposed solu-
tions using a pilot and validating the
improvement. With this comes creation
of a new process map to illustrate the
new process flow followed by a cost-
benefit analysis to ensure that the poten-
tial improvement is viable and cost-
effective. By collecting and analyzing
data on the new process, the team can
demonstrate validity of the improve-
ments. This phase will deliver solutions
to the problem and validation of those
solutions as well as implementation
and communication plans.
Questions for the Improve phase
include:
Once I know for sure what inputs
most affect my output, how do I imple-
ment changes?
How many trials do I need to run to
find and confirm the best setting/pro-
cedure for these key inputs?
C = Control
The Control phase institutionalizes
process/product improvements and
monitors ongoing performance in order
to sustain the gains achieved in the
Improve phase. During this phase the
team will develop a control strategy
based upon the results of the previous
four phases, a control plan that incor-
porates changes into the process in a
timely manner, and an updated Quali-
ty Performance Statement and train-
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