Quality

546 Pages·10.501 MB·English

by  Summers, Donna C S

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Quality
ISBN 978-1-29204-178-0
Donna C. Summers
Fifth Edition
9 781292 041780
Pearson New International Edition

Quality
Donna C. Summers
Fifth Edition
International_PCL_TP.indd 1 7/29/13 11:23 AM
ISBN 10: 1-292-04178-1
ISBN 13: 978-1-292-04178-0
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ISBN 10: 1-292-04178-1
ISBN 10: 1-269-37450-8
ISBN 13: 978-1-292-04178-0
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P E A R S O N C U S T O M L I B R AR Y
Table of Contents
1. Quality Basics
Donna C. Summers 1
2. Quality Advocates
Donna C. Summers 23
3. Quality Improvement: Problem Solving
Donna C. Summers 47
4. Statistics
Donna C. Summers 107
5. Variable Control Charts
Donna C. Summers 155
6. Process Capability
Donna C. Summers 223
7. Other Variable Control Charts
Donna C. Summers 251
8. Probability
Donna C. Summers 287
9. Quality Control Charts for Attributes
Donna C. Summers 333
10. Reliability
Donna C. Summers 383
11. Advanced Topics in Quality
Donna C. Summers 403
12. Quality Costs
Donna C. Summers 439
13. Product Liability
Donna C. Summers 463
I
455580237955
14. Quality Systems: ISO 9000, Supplier Certification Requirements, the Malcolm Baldrige Award, and Six
Sigma
Donna C. Summers 487
15. Benchmarking and Auditing
Donna C. Summers 509
16. Glossary
Donna C. Summers 525
17. Bibliography
Donna C. Summers 535
II
QUALITY BASICS
MAJOR TOPICS
j Why Quality?
j Ingredients for Success
j The Evolution of Modern Quality
j The Future of Quality
j Who Is the American Society
for Quality?
j Summary
j Lessons Learned
j Chapter Problems
j Case Study 1 Quality Evolution:
Where Are They Now?
Q
¤
LEARNING OPPORTUNITIES
1.To develop a definition for quality
2.To understand the complexities of defining quality
3.To become familiar with differing definitions of
quality from such sources as the American Society
for Quality, Dr. W. Edwards Deming, Philip Crosby,
and Armand Feigenbaum
Source: Don Kite, Parts Pups, Nov. 1971, and Reader’s
4.To gain insight into the evolution of total quality
Digest,October 1973.
management concepts
5.To become familiar with the definitions of
The cartoon above is meant to make us chuckle a little
specifications, tolerance limits, inspection,
prevention, quality, quality control, statistical about the difficulties consumers can experience in
quality control, statistical process control, total communicating what they want. But when you take a
quality management, process improvement
closer look, it isn’t so funny. How can a company ex-
6.To understand the differences between the
pect to stay in business if no connection is made be-
philosophies of inspection, quality control,
tween what the customer wants and what the company
statistical quality control, statistical process control,
total quality management, and continuous provides? This chapter begins the exploration of using
improvement, Six Sigma, and lean process improvement concepts to fulfill customers’
7.To understand the differences between actions needs, requirements, and expectations.
necessary in inspection, quality control, statistical
quality control, statistical process control, total
quality management, and continuous improvement
8.To understand that a variety of different approaches
to organizing for quality exist, including standards
like ISO 9000 and methodologies like Six Sigma
From Chapter 1 ofQuality,Fifth Edition.Donna C.S.Summers.Copyright © 2010 by Pearson Education,Inc.All rights reserved.
1
Quality Basics
WHY QUALITY? Quality Is Free,Philip Crosby discusses quality as conformance
to requirementsand nonquality as nonconformance.
Companies are always seeking an edge, something special
Quality can take many forms. The above definitions
that will set them apart from the competition. Finding an
mention three types: quality of design, quality of confor-
edge isn’t easy;competition can be in price,value,features,
mance,and quality ofperformance.Quality ofdesignmeans
nearly everything related to the products and services they
that the product has been designed to successfully fill a
provide. Let’s face it, customers have so many choices in
consumer need,real or perceived.Quality ofconformance—
today’s marketplace,ifthey’re not impressed,they’ll go else-
conformance to requirements—refers to the manufacture
where.An organization’s very survival is based on their abil-
of the product or the provision of the service that meets
ity to do what they said they would do faster, better, and
the specific requirements set by the consumer. Quality of
cheaper than anyone else.
performancemeans that the product or service performs its
From Wal-Mart and cross-docking to Toyota and just- intended function as identified by the consumer. Clearly
in-time, these companies know winning does not de- communicating the needs, requirements, and expectations
pend on a clever plan or a hot concept. It depends on of the consumer requires a more complete definition of
how regular, mundane, basic work is carried out. If you quality.
can consistently do your work faster, cheaper, and better Perhaps the most complete definition is that by
than the other guy, then you get to wipe the floor with Armand Feigenbaum, author of Total Quality Control. He
him—without any accounting tricks. Relentless opera- states that quality is a customer determination which is based
tional innovation is the only way to establish a lasting on the customer’s actual experience with the product or ser-
advantage. And new ideas are popping up all over. vice,measured against his or her requirements—stated or un-
Operational innovation isn’t glamorous. It doesn’t stated, conscious or merely sensed, technically operational or
make for amusing cocktail party conversation, and it’s entirely subjective—and always representing a moving target
unlikely to turn up in the world of glam-business jour- in a competitive market.Several key words stand out in this
nalism. It’s detailed and nerdy. This is old business, definition:
this is new business, this is real business. Get used
to it. j Customer determination:Only a customer can decide if
and how well a product or service meets his or her needs,
Michael Hammer, “Forward to Basics,”
requirements,and expectations.
Fast Company, November, 2002
j Actual experience:The customer will judge the quality of
Whether they try quality management, Six Sigma, just-
a product or service not only at the time ofpurchase but
in-time, lean, or other approaches, all organizations need
throughout usage ofthe product or service.
individuals who have been taught a solid foundation in the
fundamentals ofimprovement.The topics in this text com- j Requirements:Necessary aspects ofa product or service
called for or demanded by the customer may be stated or
prise a set of statistical and problem-solving tools that are
unstated,conscious or merely sensed.
equal to more than the sum of their parts. They provide
users with the ability to improve the way an organization j Technically operational:Aspects ofa product or service
works. may be clearly identified in words by the consumer.
Your success in your own job will be based on your j Entirely subjective:Aspects ofa product or service may
ability to find ways to design and implement improvements only be conjured in a consumer’s personal feelings.
that will enable your organization to do what they do faster,
better,and cheaper.A tall order for most of us;fortunately, Feigenbaum’s definition shows how difficult it is to
the tools and techniques taught in this text will help.Effec- define quality for a particular product or service. Quality
tive employees in effective organizations everywhere in the definitions are as different as people.In many cases,no two
world are already using them. customers will have exactly the same expectations for the
The American Society for Quality defines qualityas a same product or service. Notice that Feigenbaum’s defini-
subjective term for which each person has his or her own tion also recognizes that a consumer’s needs,requirements,
definition. In technical usage, quality can have two mean- and expectations change over time and with different situa-
ings:(1) the characteristics of a product or service that bear tions. Under some circumstances customer expectations
on its ability to satisfy stated or implied needs and(2)a pro- will not remain the same from purchase to purchase or en-
duct or service free ofdeficiencies. counter to encounter.To produce or supply a quality prod-
Many prominent professionals in the field have devel- uct or service,a company must be able to define and meet
oped definitions of quality. Dr. W. Edwards Deming, well- the customer’s reasonable needs,requirements,and expecta-
known consultant and author on the subject of quality, tions,even as they change over time.This is true whether the
describes quality as nonfaulty systems. To Dr. Deming, non- product is tangible (automobiles, stereos, or computers) or
faulty systems are error-free systems that have the ability to intangible (airplane schedules, hospital care, or repair ser-
provide the consumer with a product or service as specified. vice).Because ofFeigenbaum’s broad emphasis on customer
Dr. Joseph M. Juran, in his book Juran’s Quality Control requirements,this text will use his description of quality as
Handbook, describes quality as fitness for use. In his text, its guide.
2
Quality Basics
INGREDIENTS FOR SUCCESS Processes and Process Improvement
Corporate Culture A processtakes inputs and performs value-added activities on
those inputs to create an output(Figure 1).Most ofus do not
Companies seeking to remain competitive in today’s global
realize how many processes we perform on a day-to-day
markets must integrate quality into all aspects of their or-
basis.For instance,you go through a process when you se-
ganization. Successful companies focus on customers and
lect a movie to see.The input is the information about show
their needs, requirements, and expectations. The voice of
times and places,whom you are going with,and what crite-
the customer serves as a significant source of information
ria you have for choosing a movie.The value-added activi-
for making improvements to a company’s products and
ties are driving to the movie theater, buying a ticket, and
services.A successful enterprise has a vision statement of
watching the movie.And the output is the result,the enter-
how it sees itselfin the future.This vision serves as a guide,
tainment value ofthe movie.
enabling company leaders to create strategic plans support-
Industries have innumerable processes that enable them
ing the organization’s objectives.Aclear vision helps create
to provide products or services for customers.Think about
an atmosphere within an organization that is cohesive,with
the number ofprocesses necessary to provide a shirt by mail
its members sharing a common culture and value system
order over the Internet. The company must have a catalog
focused on the customer.Teamwork and a results-oriented,
website preparation process,a website distribution process,a
problem-solving approach are often mainstays in this type
process for obtaining the goods it plans to sell,an ordering
ofenvironment.
process,a credit-check process,a packaging process,a mail-
Every organization has “the way we do things”: tried-
ing process, and a billing process, to name a few. Other
and-true activities and methods developed to support the
processes typically found in organizations include financial
functioning of the company.But what happens when things
management;customer service;equipment maintenance and
change and a new competitor or new technology or new
installation; production and inventory control; employee
owner shakes up the status quo? How the organization
hiring, training, reviewing, firing, and payroll; software de-
adapts is crucial to its survival.Throughout this text,you’ll
velopment; and product or service design,creation,inspec-
be reading about an organization called JR Precision Shafts
tion,packaging,delivery,and improvement.
(JRPS).JRPS manufactures large precision shafts for pumps,
Many processes develop over time, with little concern
motors,and generators.
for whether it is the most effective manner in which to pro-
Three years ago this company experienced a significant
vide a product or service. To remain competitive in the
change in leadership when it was purchased by three part-
world marketplace, companies must seek out wasteful
ners. These three enterprising individuals honed their
processes and improve them. The processes providing the
knowledge of quality tools and techniques at their former
products and services will need to be quality-engineered,
companies.The culture at JRPS has changed as the people in
with the aim of preventing defects and increasing produc-
the organization buy into the “Grow the Business”vision of
tivity by reducing process cycle times and eliminating
the new owners. To support their vision, the new owners
waste.
have implemented a strategic plan that integrates a two-
The topics in this text comprise a set ofstatistical tools
pronged approach: growth by enhancing their current spe-
that provides users with the power to understand process
cialties and acquisition growth by branching out into other
behavior.With this knowledge,users can find ways to im-
manufacturing areas. Objectives to support these goals in-
prove the way their organization provides its products and
clude utilizing quality and lean manufacturing methods,
services.These tools can be applied to all sorts of processes
improving and standardizing processes,creating formal hir-
including manufacturing, services, and government. To-
ing and training systems, instituting a productive mainte-
gether,they provide a means of reducing process variation.
nance program, partnering with vendors, and enhancing
The tools themselves are fundamental to good process
technology usage. In later examples you will see how they
management.Applying them is fundamental to good man-
apply the tools and techniques taught in this text to improve
agement,period.
the way they do business.
Process
Input Output
Value-added activities
Raw materials Value-added activities Products
Components performed by individuals, Services
Instructions work groups, functions, Results
Information machines, or organizations
Criteria
FIGURE 1 Processes
3
Quality Basics
Q
¤
The Quoting Process at JRPS REAL TOOLS for REAL LIFE
Prior to new leadership at JRPS, the activity of turning a quote into boundaries of the process were set at “customer requests a quote”
a finished part had no uniform process. Since no one really knew to end at “customer receives parts.” As the team analyzed the ex-
exactly what needed to be done there were many incorrect quotes, isting methods, they realized that a better order processing method
lost quotes, missing or past due orders, incorrect or improperly was needed. The team readily considered computerizing the
priced orders, and other problems. Knowing that standardized process; however, they recognized that computerizing a non-
processes reduce the chances of errors, the new owners formed functional process wouldn’t help company performance.
ateam with the objective of defining order processing. The Q¤
variation present in a process. Methods of improving
Variation
processes by removing variation are the focus ofthis text.
In any process that produces a product or provides a ser- Product and service designers translate customer needs,
vice,rarely are two products or service experiences exactly requirements, and expectations into tangible requirements
alike. Even identical twins have their differences. Because called specifications. Specifications state product or service
variation is present in any natural process, no two products characteristics in terms ofa desired target value or dimension.
or occurrences areexactly alike.In manufacturing,variation In service industries, specifications may take the form of
is often identified as the difference between the specified descriptions of the types of services that are expected to be
target dimension and the actual part dimension.In service performed (Table 1). In manufacturing, specifications may
industries,variation may be the difference between the type be given as nominal target dimensions (Table 2),or they may
of service received and the type of service expected.Com- take the form of tolerance limits (Table 3).Tolerance limits
panies interested in providing a quality product or service show the permissible changes in the dimension of a quality
use statistical process control techniques to carefully study characteristic. Parts manufactured between the tolerance,or
the variation present in their processes. Determining why specification, limits are considered acceptable. Designers
differences exist between similar products or services and should seek input from the customer,from engineering and
then removing the causes of these differences from the manufacturing professionals, and from any others who can
processes that produce them enable a company to more assist in determining the appropriatespecifications and toler-
consistently provide a high-quality product or service. ances for a given item.
Think of it this way:If you are carpooling with an individ- To manufacture products within specifications, the
ual who is sometimes late,sometimes early,and sometimes processes producing the parts need to be stable and pre-
on time,it is difficult to plan when you should be ready to dictable.A process is considered to be under controlwhen the
leave.If,however,the person is always five minutes late,you variability (variation) from one part to another or from one
may not like it,but you can plan around it.The first person service to another is stable and predictable.Just as in the car-
exhibits a lot of variation;you never know when to expect pooling example, predictability enables those studying the
him or her.The second person,although late,has very little process to make decisions concerning the product or service.
variation in his or her process;hence you know that if you When a process is predictable,very little variation is present.
need to leave at exactly 5 P.M.,you had better tell that per- Statistical process control practitioners use a variety of tech-
son to be ready at 4:55.The best situation would be to be niques to locate the sources of variation in a process. Once
on time every time.It is this best situation at which compa- these sources are located, process improvements should be
nies are aiming when they seek to eliminate or reduce the made to eliminate or reduce the amount ofvariation present.
TABLE 1 Specifications for Banking Transactions at Teller Windows Serving
10,000 Customers Monthly
Item Specification
Customer Perception of Service/Quality 2 or Fewer Complaints per Month
Downtime of Teller Window Due to Teller Absence Not to Exceed 5 Min per Day
Deposits Not Credited 1 or Fewer per Month
Accounts Not Debited 1 or Fewer per Month
Errors on Cash In and Out Tickets 1 or Fewer per Month
Missing and Illegible Entries 2 or Fewer per Month
Inadequate Cash Reserves 2 or Fewer Occurrences per Month
4
Quality Basics
Q
➛
Specifications and Tolerance Limits at JRPS REAL TOOLS for REAL LIFE
Electric motors (Figure 2) work by converting electrical energy to fers the energy created to other devices either by direct drive or
mechanical energy. To do this, electricity flows through a copper through the use of gears. The shafts made at JRPS are made to
wire winding contained in a housing. The current sets up a rotat- order for specific customers. Engineers at JRPS work with cus-
ing magnetic field. The stator, the metal surrounding a central tomers to properly prepare drawings showing the specifications
shaft, becomes polarized and rotates on its axis. The shaft trans- and tolerance limits for the custom shafts (Figure 3).
FIGURE 2 Electric Motor
PART AASP IPSROVED: PAGE 1
AS REVISED
OPER TOLERANCES NOTES INSP.FREQ.
UNLESS OTHERWISE SPECIFIED ALL DIAMETERS, CHAMFERS,
DATE RUNOUT, PERPENDICULARITY
ISSUED 1/5
DATE ALL LENGTHS, RADII.
REVISED CENTERS, THREADS 1/10
0.40/0.60 ⋅ 45°
7.67 BOTH ENDS
7.63
CHAM
9.54
9.50
1/2 - 20 UNF - 2A THD 8.05
BOTH ENDS 8.01
155 ⋅ 15° CHAM
4.96
4.90
2.50 DIA ⋅ 60° CNTRS
EACH
BOTH ENDS
END
-B-
-A-
7.18
5.78 MIN
6.88
FULL THD
5.31 MIN
FULL THD
7.18 5.98
6.88 5.88
47.86
47.76
FIGURE 3 Custom Shaft Specifications Q➛
5