Comparing Six Sigma,
Lean, and the
Theory of Constraints
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Six Sigma
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Six Sigma claims that focusing on reduction of
variation will solve process and business problems.
By using a set of statistical tools to understand the
fluctuation of a process, management can begin to
predict the expected outcome of that process.
If the outcome is not satisfactory, associated tools
can be used to further understand the elements
influencing that process.
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Through a rigid and structured investigation
methodology, the process elements are more
completely understood.
The assumption is the outcome of the entire
process will be improved by reducing the variation
of multiple elements.
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Six Sigma problem solving methodology includes
five steps: define, measure, analyze, improve and
control (commonly known as DMAIC):
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Lean
History of Lean
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Lean thinking is sometimes called lean
manufacturing, the Toyota production system or
other names.
Lean focuses on the removal of waste, which is
defined as anything not necessary to produce
the product or service.
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There are five essential steps in lean:
1. Identify which features create value.
2. Identify the sequence of activities called the
value stream.
3. Make the activities flow.
4. Let the customer pull product or service
through the process.
5. Perfect the process.
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Theory of Constraints (TOC)
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Theory of Constraints (TOC)
TOC focuses on system improvement.
A system is defined as a series of interdependent
processes.
An analogy for a system is the chain: a group of
interdependent links working together toward the
overall goal.
The constraint is a weak link.
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Theory of Constraints (TOC)
The performance of the entire chain is limited by the
strength of the weakest link.
In manufacturing processes, TOC concentrates on
the process that slows the speed of the process.
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Theory of Constraints (TOC)
TOC consists of five steps:
1. Identify the constraint.
2. Exploit the constraint.
3. Subordinate other processes
to the constraint.
4. Elevate the constraint.
5. Repeat the cycle.
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Agile Manufacturing
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Agile Manufacturing
 Many practitioners are dismissive of Agile
Manufacturing “as a patchwork of plausible
concepts and methods.” In manufacturing, it is
dead.
 The term is still used in software development
and project management.
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Agile Manufacturing
 Roger Nagel’s team at Lehigh borrowed the
registered service mark “Agile Enterprise” …
from Crispin Vincenti-Brown and Ingersoll
Engineers.
 Their Agile Enterprise was a manufacturing
company with production organized in their
version of cells, grouped in focused factories,
as defined by Wickham Skinner.
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Business Process Reengineering
(BPR)
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Business Process Reengineering
(BPR)
Business Process Reengineering (BPR), after a
burst of popularity in the 1990s, is now a gentler
version called “Business Process Management”
(BPM).
The differences between the two are explained in a
blog post by Sweeta Anand.
BPR failed in the market because the employees of
companies that tried to implement it perceived it as a
threat, before its technical shortcomings ever had a
chance to appear.
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Business Process Reengineering (BPR)
 BPR is not about manufacturing but about business in
general, and is predicated on the assumption that any
business can be structured as a family of processes,
characterized entirely by the outputs they generate and the
inputs they use.
 In the BPR perspective, R&D is a process with product
designs as output. Manufacturing, on the other hand, is not a
process but is instead subsumed under order fulfillment. BPR
takes Wickham Skinner’s focused factory or Womack and
Jones’s value stream and expands it to all business
activities.
 BPR is intended to break down the functional silos that make
bureaucracies slow and unresponsive and replace them with
process-aligned structures that are focused on their useful
outputs.
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Business Process Reengineering (BPR)
 According to the founding fathers of BPR, Michael Hammer
and James Champy, part of the definition of a process is that
its output must be “of value to the customer,” but what is
meant by customer is ambiguous.
 Technically, BPR is simplistic, but it’s not the reason it failed.
What is absent from the BPR literature is any consideration of
the people doing the work and what happens to them as a
result of reengineering. In manufacturing, Lean improves
performance, the company grows, and the people freed up by
productivity increases are used to support the growth, and it
is essential to the success of the approach that operators not
be putting their jobs in jeopardy by participating. BPR, on the
other hand, simply reengineered people’s jobs away, which,
predictably, resulted in mutinies.
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Total Quality Management
(TQM)
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Total Quality Management
(TQM)
 TQM is an integrative philosophy of management for
continuously improving the quality of products and
processes.
 TQM is based on the premise that the quality of
products and processes is the responsibility of
everyone involved with the creation or consumption of
the products or services which are offered by an
organization, requiring the involvement of management,
workforce, suppliers, and customers, to meet or exceed
customer expectations.
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TQM
 TQM, as a watered-down version of the Japanese
TQC, became the object of the Malcolm Baldridge
National Quality Award in the US in 1988, and soon
lost credibility as a result of being given to
organizations that were notorious for bad quality.
 The spirit of TQM, however, lives on in the ISO-900x
series of standards, for which certification has been
a cost of doing business for many companies.
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Lean Six Sigma
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Lean Six Sigma
 Lean Six Sigma is a managerial concept
combining Lean and Six Sigma that results in the
elimination of waste / muda.
 The Lean Six Sigma concepts were first published
in the book titled Lean Six Sigma: Combining Six
Sigma with Lean Speed by Michael George in
2002.
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Lean Six Sigma
 Lean Six Sigma utilizes the DMAIC phases similar
to that of Six Sigma.
 The DMAIC toolkit of Lean Six Sigma comprises
all the Lean and Six Sigma tools.
 The training for Lean Six Sigma is provided
through the belt based training system similar to
that of Six Sigma. The belt personnel are
designated as white belts, yellow belts, green
belts, black belts and master black belts.
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Lean Six Sigma
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Rapid-Lean
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RapidLeanSixSigma
A common complaint of traditional Lean and Six
Sigma is that they “take too long.”
Success of RapidLeanSixSigma depends on:
speed,
simplicity, and
boldness.
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Rapid-Lean
RapidLeanSixSigma provides the tools and
techniques for making decisions and solving
problems - fast.
An organization’s early success will be
realized through engaged employees using
an empowered approach for “rapid” process
improvement.
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RapidLeanSixSigma
Integrating Lean and Six Sigma
Speed and Simplicity
 Lean
• Waste Reduction
• Velocity
 Six Sigma
• Problem Solving Methodology
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In short,
How an organization adds value.
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More Broadly, Three Big Questions
1. Where are we now?
2. Where do we want to go?
3. How do we get there?
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Quality function deployment and value
management are two techniques used to help
connect the product or service design to customer
needs. Both bring marketing, finance, operations,
design, customer and suppliers together to
systematically explore how the product performs the
function the customer
needs.
An interesting part of this investigation is that cost
can be associated with function. When marketing
and customers know the cost of specific features,
they make informed choices about the
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Parking
Lot
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Value chain
coordinated series or sequence of functional
activities necessary to transform inputs into
finished goods or services customers value
and want to buy
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Value-chain management
development of a set of functional-level
strategies that support a company’s businesslevel strategy and strengthen its competitive
advantage
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“To try and fail is at least to
learn; to fail to try is to suffer
the inestimable loss of what
might have been.”
Chester Barnard
(former CEO of New Jersey Bell Telephone)
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Successful Implementation
1.
2.
3.
4.
6.
7.
Build organizational commitment
Focus on the customer
Set goals and create incentives
Solicit input from employees
Identify opportunities for improvement
Break down barriers between functions
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1. Identify what customers want from the
good or service provided
2. Identify what is actually provided to
customers
3. Identify the gap that exists between
what the customers want and what they
get (quality gap)
4. Formulate a plan for closing the quality
gap
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Benefits
 Delighted Customers
 Benchmarking against best practices
 Identifying the right things
 Teamwork by committed employees.
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www.johnbesaw.com
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