SIX-SIGMA QUALITY
Chapter 9
9A-2
OBJECTIVES
1.
2.
3.
Understand total quality management.
Describe how quality is measured and be
aware of the different dimensions of quality.
Explain the define, measure, analyze,
improve, and control (DMAIC) quality
improvement process.
Key Six Sigma Concepts






Critical to quality: attributes most important to the customer
Defect: failing to deliver what customer wants
Process capability: what your process can deliver
Variation: what customer sees and feels
Stable operations: ensuring consistent, predictable
processes to improve what the customer sees and feels
Design for six-sigma: designing to meet customer needs
and process capability
LO 1
9-4
Total Quality Management (TQM)

Total quality management is defined
as managing the entire organization
so that it excels on all dimensions of
products and services that are
important to the customer
Malcolm Baldridge National Quality
Award



Established in 1987 by Department of Commerce
Goal is to help companies review and structure their
quality programs
Has requirement that suppliers demonstrate they
are measuring and documenting their quality
practices
LO 1
9-6
Quality Specifications



Design quality: Inherent value of the
product in the marketplace
Dimensions include: Performance, Features,
Reliability/Durability, Serviceability,
Aesthetics, and Perceived Quality.
Conformance quality: Degree to which
the product or service design
specifications are met
The Dimensions of Design Quality






Performance: primary product or service
characteristics
Features: added touches, bells and whistles,
secondary characteristics
Reliability/durability: consistency of performance
over time
Serviceability: ease of repair
Aesthetics: sensory characteristics
Perceived quality: past performance and
reputation
LO 2
9-8
Costs of Quality
Appraisal Costs
External Failure
Costs
Costs of
Quality
Internal Failure
Costs
Prevention Costs
Six-Sigma Quality



DPMO 
LO 2
Six-sigma is a philosophy and methods used
to eliminate defects
Seeks to reduce variation in the processes
One metric is defects per million
opportunities (DPMO)
Number of defects
1,000,000
Number of opportunit ies for error per unit  Number of units
Six-Sigma Methodology

Uses many of the same statistical tools as other
quality movements
 Used
in a systematic project-oriented fashion through
define, measure, analyze, improve, and control (DMAIC)
cycle
 More

detailed version of Deming PDCA cycle
Continuous improvement: seeks continual
improvement in all aspects of operations
 Also
LO 2
uses scientific method
9-11
Six Sigma Quality: DMAIC Cycle





Define, Measure, Analyze, Improve,
and Control (DMAIC)
Developed by General Electric as a
means of focusing effort on quality
using a methodological approach
Overall focus of the methodology is
to understand and achieve what the
customer wants
A 6-sigma program seeks to reduce
the variation in the processes that
lead to these defects
DMAIC consists of five steps….
9-12
Analytical Tools for Six Sigma and Continuous
Improvement: Flow Chart
Material
Received
from
Supplier
No,
Continue…
Inspect
Material for
Defects
Defects
found?
Yes
Can be used to
find quality
problems
Return to
Supplier
for Credit
9-13
Diameter
Analytical Tools for Six Sigma and Continuous Improvement:
Run Chart
Can be used to identify
when equipment or
processes are not
behaving according to
specifications
0.58
0.56
0.54
0.52
0.5
0.48
0.46
0.44
1
2
3
4
5
6
7
8
Time (Hours)
9
10 11 12
9-14
Analytical Tools for Six Sigma and Continuous
Improvement: Pareto Analysis
80%
Frequency
Can be used
to find when
80% of the
problems
may be
attributed to
20% of the
causes
Design
Assy.
Instruct.
Purch.
Training
9-15
Analytical Tools for Six Sigma and Continuous
Improvement: Check sheet
Monday
Billing Errors
Wrong Account
Wrong Amount
A/R Errors
Wrong Account
Wrong Amount
Can be used to keep track of
defects or used to make sure
people collect data in a
correct manner
9-16
Number of Lots
Analytical Tools for Six Sigma and Continuous
Improvement: Histogram
Can be used to identify the frequency of quality
defect occurrence and display quality
performance
0
1
2
Data Ranges
3
4 Defects
in lot
9-17
Analytical Tools for Six Sigma and Continuous
Improvement: Cause & Effect Diagram
Possible causes:
Machine
Man
The results
or effect
Effect
Environment
Method
Material
Can be used to systematically track backwards to
find a possible cause of a quality problem (or
effect)
9-18
Analytical Tools for Six Sigma and Continuous
Improvement: Control Charts
Can be used to monitor ongoing production process
quality and quality conformance to stated standards of
quality
1020
UCL
1010
1000
990
LCL
980
970
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
Poke-Yoke

Cutting leather
where ‘A’ placed
with no defects
or marks; ‘B’
with some; and
‘C’ with more
than B allowed.
Visual Management
9-21
Other Six Sigma Tools


Failure Mode and Effect Analysis (DMEA) is
a structured approach to identify, estimate,
prioritize, and evaluate risk of possible
failures at each stage in the process
Design of Experiments (DOE) a statistical
test to determine cause-and-effect
relationships between process variables and
output
9-22
Six Sigma Roles and Responsibilities
1.
2.
3.
4.
Executive leaders must champion
the process of improvement
Corporation-wide training in Six
Sigma concepts and tools
Setting stretch objectives for
improvement
Continuous reinforcement and
rewards
9-23
External Benchmarking Steps
1. Identify those processes needing
improvement
2. Identify a firm that is the world leader
in performing the process
3. Contact the managers of that company
and make a personal visit to interview
managers and workers
4. Analyze data
ANY QUESTIONS?