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CHAPTER 9
Process Improvement and Six Sigma
Teaching Notes
This chapter brings process improvement and the Six Sigma concept into a sharp focus, and builds
on the need to integrate a performance management framework with operational requirements in
managing quality. In this chapter, we introduce the statistical basis for Six Sigma, and outline the
requirements for Six Sigma implementation. This chapter also extends the concepts of Chapter 5 on
process focus and Chapter 6 on statistical thinking, and introduces the 7 QC Tools used for
continuous improvement, Six Sigma, and lean.
Key objectives for this chapter are:
• To review the definition of a process as a sequence of linked activities that is intended to
achieve some result, such as producing a good or service for a customer within or outside
the organization. Generally, processes involve combinations of people, machines, tools,
techniques, materials, and improvements in a defined series of steps or actions.
• To fully understand the concept of breakthrough, defined as the accomplishment of any
improvement that takes an organization to unprecedented levels of performance. Six
Sigma projects often focus on breakthrough improvements that add value to the
organization and its customers through systematic approaches to problem solving.
• To learn that structured improvement methodologies typically consist of four steps:
redefining and analyzing a problem, generating ideas, evaluating and selecting ideas, and
implementing ideas. Common approaches are the Deming cycle, creative problem
solving, Six Sigma DMAIC, TRIZ, custom improvement methodologies, and many
others.
• To learn the Six Sigma philosophy, which can be described as a business improvement
approach that seeks to find and eliminate causes of defects and errors in manufacturing
and service processes by focusing on outputs that are critical to customers and a clear
financial return for the organization. The term six sigma is based on a statistical measure
that equates to 3.4 or fewer errors or defects per million opportunities.
• To compare some of the contrasting features between TQM and Six Sigma which
include: TQM is based largely on worker empowerment and teams; Six Sigma is owned
by business leader champions. TQM activities generally occur within a function, process,
or individual workplace; Six Sigma projects are truly cross-functional. TQM training is
generally limited to simple improvement tools and concepts; Six Sigma focuses on a
more rigorous and advanced set of statistical methods and DMAIC methodology. TQM is
focused on improvement with little financial accountability; Six Sigma requires a
verifiable return on investment and focus on the bottom line.
• To understand that a six sigma quality level corresponds to a process variation equal to
half of the design tolerance while allowing the mean to shift as much as 1.5 standard
Process Improvement and Six Sigma 2
deviations from the target. A k-sigma quality level satisfies the equation: k × process
standard deviation = tolerance range/2
• To learn that a defect, or nonconformance, is any mistake or error that is passed on to
the customer. A unit of work is the output of a process or an individual process step. A
common measure of output quality is defects per unit (DPU), computed as Number of
defects discovered/Number of units produced, and in Six Sigma metrics, defects per
million opportunities (dpmo) = DPU 1,000,000/opportunities for error. A six-sigma
quality level corresponds to at most 3.4 dpmo which is equivalent to a process variation
equal to half of the design tolerance, while allowing the mean to shift as much as 1.5
standard deviations from the target. The sigma level can easily be calculated on a
spreadsheet using the Excel formula = (1 – NORM.DIST(sigma level, 1.5, 1, TRUE))*
1000000 The sigma level can be calculated on a spreadsheet using the Excel formula
=NORM.S.INV(1 – dpmo/1,000,000) + 1.5.
• To learn about and practice problem solving — correcting deviations between what is
happening and what should be happening. Quality related problems often fall into five
categories: conformance problems, unstructured performance problems, efficiency
problems, product design problems, and process design problems.
• To appreciate that a structured problem solving process provides employees and teams
with a common language and a set of tools to communicate with each other.
• To develop understanding of the Six Sigma DMAIC process stages of: 1) Define – the
process of drilling down to a more specific problem statement is sometimes called
project scoping; 2) Measure – collecting good data, observation, and careful listening; 3)
Analyze – focuses on why defects, errors, or excessive variation occur, and focuses on the
root cause; 4) Improve – focuses on idea generation, evaluation, and selection; 5)
Control – focuses on how to maintain the improvements.
• To explore the use of Pareto distributions which are histograms of the data from the
largest frequency to the smallest. Pareto diagrams help analysts to progressively focus in
on the most appropriate problems.
• To understand a type of high-level process map called a SIPOC diagram. SIPOC stands
for Suppliers-Inputs-Process-Outputs-Customers. SIPOC maps provide a broad overview
of the key elements in the process and help to explain who is the process owner, how
inputs are acquired, who the process serves, and how it adds value.
• To understand the benefits of a project charter, which defines the project, its objectives,
and deliverables, and represents a contract between the project team and the sponsor. A
project charter will typically define the problem in a simple fashion, the project objective,
the project team and sponsor, the customers and CTQs on which the project focuses,
existing measures and performance benchmarks, expected benefits and financial
justification, a project timeline, and the resources needed to carry out the project
• To appreciate that projects are the vehicles that are used to organize team efforts and to
implement the DMAIC process. Being able to manage a large portfolio of projects, as
would be found in Six Sigma environments, is vital to organizational success.
• To know that project teams are a vital part of Six Sigma efforts and are comprised of
champions, master black belts, black belts, green belts, other team members, who each
provide different levels of knowledge and expertise in solving problems.
Process Improvement and Six Sigma 3
• To study factors that should be considered when selecting Six Sigma projects including:
financial return, impacts on revenues and market share, impacts on customers and
organizational effectiveness, probability of success, impacts on employees, and strategic
fit.
• To introduce Six Sigma tools, in the light of two unique features of DMAIC: its emphasis
on customer requirements and the disciplined use of statistical and other types of
improvement tools. Typical types of tools include elementary statistical tools, advanced
statistical tools, product design and reliability, measurement, process control, process
improvement, and implementation and teamwork.
• To become familiar with, and learn to apply the “seven QC tools” and related tools for
quality problem solving. The seven tools include flowcharts or process maps, run charts,
data sheets or check sheets, histograms, cause-and-effect diagrams, Pareto diagrams,
scatter diagrams and control charts.
• To understand the concept of lean production, which refers to approaches initially
developed by the Toyota Motor Corporation that focus on the elimination of waste in all
forms, including defects requiring rework, unnecessary processing steps, unnecessary
movement of materials or people, waiting time, excess inventory, and overproduction. In
service contexts, lean production is often called lean enterprise. Some of the key tools
used in lean production are the 5S’s; visual controls; efficient layout and standardized
work; pull production; single minute exchange of dies (SMED); total productive
maintenance; source inspection; and continuous improvement.
• To comprehend that tools and approaches used in Six Sigma and lean production are
different, yet complementary. Lean is focused on efficiency by reducing waste and
improving process flow while Six Sigma is focused on effectiveness by reducing errors
and defects. Lean Six Sigma is a synthesis of the best practices of both Six Sigma and
lean production and has gained considerable favor among practitioners in many
organizations.
• To understand that although Six Sigma was developed in the manufacturing sector, it can
easily be applied to a wide variety of transactional, administrative, and service areas.
ANSWERS TO QUALITY IN PRACTICE FEATURES
An Application of Six Sigma to Reduce Medical Errors
1. How did the team use process mapping as a key part of the Six Sigma process? What
value did process mapping have?
Process mapping was an essential early step for Froedtert Hospital to take in order to identify the
Process Improvement and Six Sigma 4
2. Why were the teams and task forces multidisciplinary in nature? What benefits does this
approach have?
The teams and task forces were multidisciplinary because the processes crossed organizational
boundaries. For example, the IV’s could be used in emergency rooms, surgical theatres, maternity
wards, etc. They would be of interest and concern to physicians, nurses, pharmacists, and
Applying Quality Improvement Tools to an Order Fulfillment Process
1. Explain how the process the team followed might align with DMAIC, the Deming Cycle,
and the creative problem-solving process.
The DMAIC process from this chapter, and the Deming cycle and the creative problem-solving
process are basically parallel statements of statistical thinking used to solve problems. Although not
a perfect fit, these processes can be compared in a parallel fashion as follows:
Six Sigma
Deming
Creative Problem-solving
Define
Plan
Understanding the “mess”
Measure
Do
Finding facts
Analyze
Study
Identifying specific problems
Generating ideas
Improve
Developing solutions
Control
Act
Implementation
In the case study the team defined the problem (initially) as “discover ways to reduce order
processing time so that at least 98% of orders would be shipped on time (within 24 hours of receipt).
They then sought to understand the process by gathering facts – the data of times for processing 50
orders. They then analyzed the data in a search for the causes for variation and select the most likely
2. What might the team do if the reduction in order processing time resulting from the
introduction of the longer carts was not large enough to achieve the goal of having 98 percent
of the orders meet the 24-hour deadline?
Although not mentioned in the case, Deming would suggest that the cycle could be repeated over
and over for “continuous improvement.” Therefore, if sufficient time had not been shaved off the
Process Improvement and Six Sigma 5
average time for picking each order, then additional analysis might produce further methods
improvements to reduce the time.
3. Suppose packing parts is now the activity responsible for the greatest delays in processing
an order. How might this affect the project organization and next steps?
Alternatively, the packing process might be examined for improvements. The same set of problem-
ANSWERS TO REVIEW QUESTIONS
1. Explain the four themes that different improvement methodologies share. How are they
reflected in the Deming cycle, creative problem-solving process, and DMAIC?
The common themes that can be applied to the Deming cycle, creative problem solving and the
DMAIC process of Six Sigma are:
1. Redefining and analyzing the problem: Collect and organize information, analyze the
data and underlying assumptions, and reexamine the problem for new perspectives, with
the goal of achieving a workable problem definition.
2. Generating ideas: “Brainstorm” to develop potential solutions.
3. Evaluating and selecting ideas: Determine whether the ideas have merit and will achieve
the problem solver’s goal.
4. Implementing ideas: Sell the solution and gain acceptance by those who must use them.
The Deming cycle, as represented in the PDSA process, provides a basic framework for
developing, testing and implementing changes to any process that will lead to improvement. The
creative problem solving process recognizes that while many creative ideas seemingly come at
moments of inspiration, systematic approaches can refine thinking and help prepare for those
2. Explain the steps of the Deming cycle.
The Deming cycle is a simple adaptation of the scientific method for process improvement. In
1939, Walter Shewhart first introduced this as a three-step process of specification, production,
and inspection for mass production that “constitute a dynamic scientific process of acquiring
knowledge.” The “Deming wheel” consisted of:
1. Design the product with appropriate tests.
2. Make the product and test in the production line and in the laboratory.
Process Improvement and Six Sigma 6
3. Sell the product.
3. What is Six Sigma? Briefly outline its history at Motorola and General Electric.
Six Sigma can be described as a business improvement approach that seeks to find and eliminate
causes of defects and errors in manufacturing and service processes by focusing on outputs that
are critical to customers and a clear financial return for the organization. The term six sigma is
based on a statistical measure that equates to 3.4 or fewer errors or defects per million
opportunities. We use “six sigma” to refer to the statistical measure and “Six Sigma” to refer to
the management philosophy. The late Bill Smith, a reliability engineer at Motorola, is credited
with originating the concept during the mid-1980s and selling it to Motorola’s CEO, Robert
Galvin. Smith noted that system failure rates were substantially higher than predicted by final
product test, and suggested several causes, including higher system complexity that resulted in
more opportunities for failure, and a fundamental flaw in traditional quality thinking. He
concluded that a much higher level of internal quality was required and convinced Galvin of its
importance. Motorola set the following goal in 1987:
4. List the key principles of the Six Sigma philosophy. How does it differ from TQM?
The core philosophy of Six Sigma is based on the following concepts:
1. Think in terms of key business processes and customer requirements with a clear focus on
overall strategic objectives.
2. Focus on corporate sponsors responsible for championing projects, support team activities,
Process Improvement and Six Sigma 7
help to overcome resistance to change, and obtain resources.
3. Emphasize such quantifiable measures as defects per million opportunities (dpmo) that can
be applied to all parts of an organization: manufacturing, engineering, administrative,
software, and so on.
As such, Six Sigma is quite different from the older TQM philosophy. Some of the contrasting
features between TQM and Six Sigma include:
• TQM is based largely on worker empowerment and teams; Six Sigma is owned by
business leader champions.
5. Explain the theoretical basis for the six-sigma 3.4 dpmo measure. How does it relate to
process capability concepts?
A six-sigma quality level corresponds to a process variation equal to half of the design tolerance
6. What is Kepner and Tregoe’ s definition of a problem?
Successful quality improvement depends on the ability to identify and solve problems.
According to Kepner and Tregoe, a problem is a deviation between what should be happening
7. List and explain the five categories into which all quality problem solving can be
classified. Provide some quality-related examples in each category.
All quality problem-solving can be classified into the following five categories:
Process Improvement and Six Sigma 8
1. Conformance problems are defined by unsatisfactory performance by a well-specified
system. Users are not happy with system outputs, such as quality or customer service
levels. Traditional quality improvement tools and Six Sigma methods are often used
here.
2. Efficiency problems result from unsatisfactory performance from the standpoint of
stakeholders other than customers. Typical examples are cost and productivity issues.
Lean tools are often used to address such problems.
8. Explain the role of projects in Six Sigma. How are Six Sigma teams typically organized?
Projects are the vehicles that are used to organize and to implement Six Sigma. Although
projects are set up as temporary organization structures, their flexibility allows cross-functional
teams to complete significant work in minimum time, if well managed. One of the challenges of
implementing Six Sigma projects is to coordinate them with normal work activities. Six Sigma
teams are comprised of several types of individuals:
• Champions: Senior-level managers who promote and lead the deployment of Six Sigma
in a significant area of the business.
9. Explain the knowledge and management expertise that Green Belts, Black Belts, and
Master Black Belts should have?
Green belts, black belts, and master black belts should have broad knowledge and management
expertise. Specifically, the following are important for their respective roles:
• Champions: Champions understand the philosophy of Six Sigma, select projects, set
objectives, allocate resources, and select and mentor teams. Champions own Six Sigma
projects and are responsible for their completion and results; typically they also own the
Process Improvement and Six Sigma 9
process that the project is focused on improving. More importantly, champions work
toward removing barriers—organizational, financial, personal—that might inhibit the
successful implementation of a Six Sigma project.
10. Discuss factors that should be considered when selecting Six Sigma projects.
Factors that should be considered when selecting Six Sigma projects include the following:
• Financial return, as measured by costs associated with quality and process performance,
and impacts on revenues and market share
11. Explain the structure and purpose of the A3 Report that Toyota created. How does it
support the DMAIC process?
The A3 Report, was created by Toyota to succinctly consolidate and visualize information for
identifying and solving quality problems. They exploit simplicity and visualization to facilitate
process improvement. A3 reports are printed on a single sheet of 11-inch by 17-inch paper and
contain text, pictures, diagrams, and charts, designed to enrich and clarify the problem and data.
The reports are divided into seven sections which roughly follow the flow of the DMAIC
process:
1. Theme, which succinctly states the problem being addressed.
2. Background, which contains a description of all pertinent information needed to
Process Improvement and Six Sigma 10
achieve the improvements.
7. Follow-Up, which lists activities that will need to be completed after implementation
along with the results of the implementation. It might also document obstacles encountered
during implementation to provide a basis for learning.
12. Explain the concept of Pareto analysis. How is a Pareto distribution created?
Pareto analysis can help identify the most important issue among a mess of symptoms is Pareto
analysis. Joseph Juran coined the term the “Pareto principle,” and popularized it in 1950 after
observing that a high proportion of quality issues resulted from only a few causes. He named this
technique after Vilfredo Pareto (1848–1923), an Italian economist who determined that 85
13. What is a SIPOC diagram? How is it used in DMAIC?
A SIPOC diagram is a special high-level process map. SIPOC stands for Suppliers-Inputs-
Process-Outputs-Customers. SIPOC maps provide a broad overview of the key elements in the
process and help to explain who is the process owner, how inputs are acquired, who the process
serves, and how it adds value. Inputs are goods and services required by a process to generate its
14. State the typical elements that make up a project charter.
A project charter defines the project, its objectives, and deliverables, and represents a contract
between the project team and the sponsor. A project charter will typically define the problem in
15. What is an operational definition? Why is it important?
It is important to develop operational definitions for all performance measures that will be
Process Improvement and Six Sigma 11
used. An operational definition can be thought of as one which is clear, unambiguous, and often
contains a quantitative or qualitative objective that must be met. For example, what does it mean
to have “on–time delivery”? Does it mean within one day of the promised time? One week? One
16. Explain different types of check sheets and how they are used.
There are a number of types of check sheets. They are special types of data collection forms,
which are useful because the results may be interpreted on the form directly without additional
processing. Some types include: 1) check sheets used in manufacturing and are designed to
create a histogram of continuous measurements as they are collected. Such a check sheet can
also include specification limits, making it easy to evaluate process capability and the percentage
of nonconforming output.
A second type of check sheet for defective items shows the type of defect and a tally.
Such a check sheet can be extended to include a time dimension so that data can be monitored
17. What is a value stream map and how does it differ from an ordinary flowchart?
A special type of process map is a value stream map. The value stream refers to all activities
involved in designing, producing, and delivering goods and services to customers. These
activities include the flow of materials throughout the supply chain, transformation activities in
the manufacturing or service delivery process, and the flow of information needed to support
these activities. A value stream map shows the process flows in a manner similar to an ordinary
18. What is root cause analysis? Describe some tools that are useful in identifying a root
cause.
The goal of problem solving is to identify the fundamental causes of problems in order to correct
Process Improvement and Six Sigma 12
them—the root causes. NCR Corporation defines root cause as “that condition (or interrelated
set of conditions) having allowed or caused a defect to occur, which once corrected properly,
permanently prevents recurrence of the defect in the same, or subsequent, product or service
generated by the process.” As with a medical analogy, eliminating symptoms of problems
usually provides only temporary relief; eliminating root causes provides long-term relief.
19. Why is brainstorming an important tool in the Improvement phase of DMAIC?
Brainstorming, a useful group problem-solving procedure for generating ideas, was proposed by
Alex Osborn “for the sole purpose of producing checklists of ideas” that can be used in
developing a solution to a problem. With brainstorming, no criticism is permitted, and people are
20. Describe the key tools used in lean production.
The key tools used in lean production, include:
• The 5S’s. The 5S’s are derived from Japanese terms: seiri (sort), seiton (set in order),
seiso (shine), seiketsu (standardize), and shitsuke (sustain). They define a system for
workplace organization and standardization. Sort refers to ensuring that each item in a
workplace is in its proper place or identified as unnecessary and removed. Set in
order means to arrange materials and equipment so that they are easy to find and use.
• Visual controls. Visual controls are indicators for tools, parts, and production
activities that are placed in plain sight of all workers so that everyone can understand
the status of the system at a glance. Thus, if a machine goes down, or a part is
Process Improvement and Six Sigma 13
method reduces wasted human movement and energy.
• Pull production. In this system (also known as kanban or just-in-time), upstream
suppliers do not produce until the downstream customer signals a need for parts.
• Single minute exchange of dies (SMED). SMED refers to rapid changeover of tooling
and fixtures in machine shops so that multiple products in smaller batches can be run
on the same equipment. Reducing setup time adds value to the operation and
21. How did Lean Six Sigma evolve? How does it differ from the original concept of Six
Sigma?
Lean production refers to approaches that originated at the Ford Motor Company in the early
1900s, but which were refined and modernized by the Toyota Motor Corporation later in the
century. Lean approaches focus on the elimination of waste in all forms, including defects
requiring rework, unnecessary processing steps, unnecessary movement of materials or people,
waiting time, excess inventory, and overproduction. A simple way of defining it is “getting more
done with less. It involves identifying and eliminating non-value-added activities throughout the
22. Why is Lean Six Sigma especially useful in services? Cite some examples.
Lean Six Sigma (LSS) can provide substantial benefits to services. Important similarities exist
between manufacturing and nonmanufacturing processes. Both types of processes have “hidden
factories,” those places where the defective product is sent to be reworked or scrapped (revised,
corrected, or discarded in nonmanufacturing terms). Find the hidden factory and you also find
opportunities to improve the process. There are numerous applications of LSS in services,
including:
• At CNH Capital, a project was implemented to decrease asset management cycle time
in posting repossessions to a bid list and remarketing website. Cycle time was
Process Improvement and Six Sigma 14
reduced 75 percent, from 40 days to 10 days, resulting in significant ongoing dollar
savings.
ANSWERS TO DISCUSSION QUESTIONS
1. The January 22, 2001, issue of Fortune contained an article “Why You Can Safely
Ignore Six Sigma,” that was highly critical of Six Sigma. Here are some of the criticisms
levied against Six Sigma:
a. The results often don’t have any noticeable impact on company financial statements.
Thus, Six Sigma success doesn’t correlate to higher stock value. This criticism
applies to 90 percent of the companies that implement Six Sigma.
b. Only early adopters can benefit.
c. Six Sigma focuses on defects, which are hard to objectively determine for service
businesses.
d. Six Sigma can’t guarantee that your product will have a market.
As with many other criticisms of quality improvement efforts, this Fortune article focuses on
what happens if organizations fail to apply the basic quality and leadership concepts. Deming
frequently said: “There is no instant pudding.” in making quality work. Thus, the statements in
the article are largely bogus.
a. If Six Sigma has no noticeable impact on company financial statements, it’s because not
many significant projects have been performed, but simply those addressing the “low–
Process Improvement and Six Sigma 15
hanging fruit.” One of the strengths of the Six Sigma concept is that it documents
financial impacts of the projects.
2. Some of the key processes associated with business activities for a typical company
include sales and marketing, supply chain management, managing information
technology, and managing human resources. What types of Six Sigma projects might be
considered in order to improve each of these activities?
Six Sigma projects can be devised to improve activities and processes in such areas as:
Sales and marketing projects
Perceived product value
Overall customer satisfaction
Sales force effectiveness
Complaint reduction
Gains and losses of customers
Customer awards/recognitions
Supply chain management projects
Internal supplier quality measurements
Defect levels
Response time
Customer ratings of prod/service performance
Managing information technology projects
Internal information technology quality measurements
Defect levels
Response time
Customer ratings of service performance
Improvement of procurement process for software and hardware
Human resource projects
Root cause analysis and reduction of absenteeism
Root cause analysis and reduction of turnover
Measurement and improvement of employee satisfaction
Measurement and improvement of training effectiveness
Grievance reduction
Process Improvement and Six Sigma 16
Suggestion system improvement
Safety improvement
3. Suggest a set of CTQs that might influence overall service satisfaction for service at an
automobile dealership.
A set of CTQs that might influence overall service satisfaction for service at an automobile
dealership includes the dimensions of service quality found in Chapter 4, as well as a couple of
related ones (timeliness and time):
Empathy – ability to understand and empathize with the problems of customers who may
or may not have the technical know-how to explain them in mechanical terms
Timeliness – return of the car at the time promised is essential to busy customers
4. “Resistance to change ” is a common theme in the behavioral sciences. What part do you
believe that resistance to change plays in management ’s fostering of successful versus
unsuccessful adoptions of Six Sigma approaches? What impact does workers’
resistance or lack of resistance have?
“Resistance to change” is to be expected in introduction of a new approach, such as Six Sigma,
and plays a key part in successful adoption of the concept. As pointed out in Chapter 6, keys to
overcoming resistance to change, more often held by managers than by first-line employees, are: a)
5. List some of the common processes that a student performs. How can these processes be
improved using a process improvement approach?
Processes that students might encounter at their college or university might include studying,
preparing for exams, conducting research, working with student organizations, planning events, and
Process Improvement and Six Sigma 17
6. Discuss how DMAIC might be used in your personal life. For example, how could you
use it if you wanted to lose weight or improve a skill such as playing a musical instrument?
DMAIC might be used in your personal life in a variety of ways. If you want to improve a skill
such as playing a musical instrument, you would define the specific objective, such as learning
the scales on a guitar, and the finger patterns for three chords. The measurement process might
7. Discuss what would be the most appropriate tool to use to attack each of these problems:
a. A copy machine suffers frequent paper jams and users are often confused as to how
to fix the problem.
b. The publication team for an engineering department wants to improve the accuracy
of
its user documentation but is unsure of why documents aren’t error-free.
c. A rental car agency is getting numerous complaints about the length of time that
customers have to wait to obtain a car. They need to get a better handle on the
factors that relate to the wait time.
d. A kitchen in a restaurant always seems to be getting orders mixed up and plated
incorrectly.
e. A local zoo wants to understand where its guests come from in order to better target
marketing efforts.
f. A contracting agency wants to investigate why they had so many changes in their
contracts. They believe that the number of changes may be related to the dollar
value of the original contract or the days between the request for proposal and the
contract award.
g. A travel agency is interested in gaining a better understanding of how call volume
varies by time of year in order to adjust staffing schedules.
The appropriate tools to attack the problems would be:
a. If the significant causes of the copier jams are known, use a flowchart to show the
method for clearing each type of jam so that users would know how to fix them.
b. Use a cause-effect diagram to identify the problem and to focus in on the most
Process Improvement and Six Sigma 18
8. How can lean concepts be applied in a classroom?
Lean concepts may have applicability to classrooms. For example, students might use the 5S’s to
9. The Six Sigma philosophy seeks to develop technical leadership through “Belt” training,
then use it in team-based projects designed to improve processes. To what extent are these two
concepts (technical experts versus team experts) at odds? What must be done to prevent them
from blocking success in improvement projects?
Ideally, the skills of technical experts (Green or Black Belts) will complement those of team
members (often called subject matter experts, or SME’s). The two types of experts may be at odds if
they cannot agree ways to analyze problems, what their measures show, and how to implement
10. How might a Six Sigma project be done to improve a registration process in a
university? An admission process?
The DMAIC process for a university registration process design/improvement should begin with
customer needs and expectations (expected quality), and end with what the customer sees and
believes the quality of the product to be (perceived quality). These might include characteristics
as follows:
Attributes Technical Requirements
Convenience Time, dates, internet, phone
Speed Process standards
Costs Fees
Process Improvement and Six Sigma 19
Expected quality needs to be considered in the Define stage based on what the customer assumes
will be received from the process as a reflection of the customer’s needs. The university must
focus on the key dimensions that are reflected in specific customer needs. If these expectations are
not identified correctly or are misinterpreted, then the final product will not be perceived to be of
high quality by customers. For registration, this will typically involve availability of classes,
timeliness of the process, time required to complete the process, etc.
11. How can a manager effectively balance the key components of a Six Sigma
implementation design related to who, what, where, when, why, and how it could be done?
To balance the who, what, where, when why, and how of Six Sigma implementation, a manager,
assisted by the team, must evaluate them and select the most promising. This includes confirming
that the proposed solution will positively impact the key process variables and the CTQ’s, and
12. In 1995, Jack Welch, who was then CEO of General Electric, sent a memo to his senior
managers telling them that they would have to require every employee to have started Six
Sigma training to be promoted. Furthermore, 40 percent of the managers’ bonuses were to
be tied to the successful introduction of Six Sigma. Do you believe that this directive was a
motivational action, or did it violate W. Edwards Deming’s maxim that managers and
Process Improvement and Six Sigma 20
leaders must “cast out fear”? Why or why not?
An argument can be made on either side of the question. On the positive side, Welch’s action
could be taken as a clear signal that Six Sigma was going to be a vital process at G.E. and used
13. A consultant told the story of two Six Sigma teams that made separate presentations on
how they would improve processes in their own areas. At the end of the second presentation,
the consultant asked a basic question that stopped both Black Belt team leaders in their
tracks: “Haven’t you both just proposed making improvements based on eliminating parts of
processes in the other group’ s areas? It seems that the implementation costs in one area will
cancel out the savings in the other area!” What had the Black Belts failed to recognize? What
would you recommend to prevent this situation from happening in other organizations?
The problem of proposing changes in one area that cancels out gains in the other area would appear
to be due to a lack of communication between the two project teams. However, it may also have
SOLUTIONS TO PROBLEMS
1. Multisigma Corp. has a process they believe is operating near a six-sigma level and
want to verify this. If the specification for a critical part in the process is 2.80 cm ± 0.10 and
the standard deviation for the process is 0.02, at what sigma level is this process operating?
The specification limits for the process are LSL = 2.70 and USL = 2.90. Using equation (9.1),
we obtain:
2. Neverflounder Fish Company advertises that 99.4% of their fish were caught within the
past 36 hours. How many dpmo does this claim represent? At what sigma level is this
process operating?
The nonconformance rate is 1.0 – .994 = 0.006. Thus, 0.006 x 1,000,000 = 6,000 dpmo.