• Six Sigma is a business management strategy,
originally developed by Motorola in 1986. Six
Sigma became well known after Jack
Welch made it a central focus of his business
strategy at General Electric in 1995, and today
it is widely used in many sectors of industry.
• Six Sigma seeks to improve the quality of process outputs
by identifying and removing the causes of defects (errors)
and minimizing variability in manufacturing and business
• It uses a set of quality management methods,
including statistical methods, and creates a special
infrastructure of people within the organization ("Black
Belts", "Green Belts", etc.) who are experts in these
methods. Each Six Sigma project carried out within an
organization follows a defined sequence of steps and has
quantified financial targets (cost reduction and/or profit
History of Six Sigma
• 1984 Bob Galvin of Motorola showed the first objectives of Six Sigma
– 10x levels of improvement in service and quality by 1989
– 100x improvement by 1991
– Six sigma capability by 1992
– Bill Smith, an engineer from Motorola, is the person credited as the
father of Six Sigma
• 1984 Texas Instruments and ABB work closely with Motorola to further
develop Six Sigma.
• 1994 Application experts leave Motorola.
• 1995 AlliedSignal begins Six Sigma initiative as directed by Larry Bossidy
– Captured the interest of Wall Street
• 1995 General Electric, led by Jack Weish, begun the most widespread
undertaking of six sigma ever attempted.
• 1997 to present six sigma spans industries worldwide
History of Six Sigma
• Simplistically, Six Sigma was a program that was generated
around targeting a process Mean (average) six Standard
Deviations away from the closest specification limit.
• Six sigma created a realistic and quantifiable goal in terms
of its target of 3.4 defects per million opportunities. It is
also accompanied by the methodology to attain this goal.
• The methodology was a problem solving strategy made up
of four steps: measure, analyze, improve and control.
• When GE launched six sigma they improved the
methodology by including the Define Phase.
Features That Set Six Sigma Apart
From Previous Quality Improvement
• A clear focus on achieving measurable and quantifiable
financial returns from any Six Sigma project.
• An increased emphasis on strong and passionate
management leadership and support.
• A special infrastructure of "Champions", "Master Black
Belts", "Black Belts", "Green Belts", "Red Belts" etc. to
lead and implement the Six Sigma approach.
• A clear commitment to making decisions on the basis
of verifiable data, rather than assumptions and
Methods for Six Sigma
• Six Sigma projects follow two project methodologies
inspired by Deming's Plan-Do-Check-Act Cycle. These
methodologies, composed of five phases each, bear
the acronyms DMAIC and DMADV.
• DMAIC is used for projects aimed at improving an
existing business process. DMAIC is pronounced as
• DMADV is used for projects aimed at creating new
product or process designs. DMADV is pronounced as
• The DMAIC project methodology has five phases:
• Define the problem, the voice of the customer, and the project
• Measure key aspects of the current process and collect relevant
• Analyze the data to investigate and verify cause-and-effect
relationships. Determine what the relationships are, and attempt to
ensure that all factors have been considered. Seek out root cause of
the defect under investigation.
• Improve or optimize the current process based upon data analysis
using techniques such as design of experiments, poka yoke or
mistake proofing, and standard work to create a new, future state
process. Set up pilot runs to establish process capability.
• Control the future state process to ensure that any deviations from
target are corrected before they result in defects.
Implement control systems such as statistical process control,
production boards, visual workplaces, and continuously monitor the
DMADV or DFSS
• The DMADV project methodology, also known
as DFSS ("Design For Six Sigma"), features five phases:
• Define design goals that are consistent with customer
demands and the enterprise strategy.
• Measure and identify CTQs (characteristics that
are Critical To Quality), product capabilities, production
process capability, and risks.
• Analyze to develop and design alternatives, create a highlevel design and evaluate design capability to select the
• Design details, optimize the design, and plan for design
verification. This phase may require simulations.
• Verify the design, set up pilot runs, implement the
production process and hand it over to the process
Six Sigma Strategy
Six Sigma places the emphasis on the process
– Using a structured, data driven approach centered on
the customer, Six sigma can resolve business problems
where are rooted, for example;
• Month end reports
• Capital expenditure approval
• New hire recruitments
Six sigma is a Breakthrough Strategy
– Widened the scope of the definition of quality
• Includes the value and the utility of the product/services to
both the company and the customer.
Conventional definition of quality focused on
conformance to standards.
Conventional strategy was to create a product or
service that met certain specifications.
– Assumed that if products and services were of good
quality, then their performance standards were
– Rework was required to ensure final quality
– Efforts were overlooked and un-quantified (time,
money, equipment usage, etc.)
Problem Solving Strategy
• Understanding the relationship between independent
variables and the dependent variable.
• Identifying the vital few independent variables that
effect the dependent variable.
• Optimizing the independent variables so as to control
our dependant variable(s).
• Monitoring the optimized independent variables.
There are many examples to describe dependent and
• We describe the concept in terms of the equation.
Y = f (Xi)
This simply states that Y is the function of
X’s. In other words Y is dictated by the X’s.
Y = f (Xi)
Which process variables (Causes i.e. X) have
critical impact on the output (Effect i.e. Y)?
Example of “Closing of a grocery store”:
Time to Close = f (Trial Balance, Correct
Accounts Applied, Sub Accounts, Credit
Memos, Entry Mistakes, Xn )
If we are so good at the X’s then why do
we constantly test and inspect the Y ?
Six Sigma Strategy
We use a variety of six sigma tools to help us separate the
“vital few” variables effecting our Y from the “trivial many”.
Some processes contain many variables. However our Y is not
effected by all of them. By focusing on vital few we
instantly gain leverage.
• Define, Measure, Analyze, Improve, Control Problem
• Pareto Chart
• Cause & Effect Diagram
• Failure Mode Effect Analysis (FMEA)
• 5 Whys
Six Sigma Roles & Responsibilities
There are many roles and responsibilities for
successful implementation of Six Sigma.
• Executive Leadership
• Champion / Process
• Master Black Belt
• Black Belts
• Green Belts
• Yellow Belts
Where to do Six Sigma From?
Pakistan Institute Quality Control