Transcript Chapter 1

Chapter 10
Quality Improvement
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
1
Traditional Economic Model
of Quality of Conformance
Total cost
Cost due to
nonconformance
“optimal level” of quality
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
Cost of
quality
assurance
100%
2
Modern Economic Model
of Quality of Conformance
Total cost
Cost due to
nonconformance
Cost of
quality
assurance
100%
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
3
Problem Solving
• Problem: any deviation between what
“should be” and what “is” that is important
enough to need correcting
– Structured
– Semistructured
– Ill-structured
• Problem Solving: the activity associated
with changing the state of what “is” to what
“should be”
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
4
Quality Problem Types
1.
2.
3.
4.
5.
Conformance problems
Unstructured performance problems
Efficiency problems
Product design problems
Process design problems
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
5
Problem Solving Process
1. Redefining and analyzing the
problem
2. Generating ideas
3. Evaluating and
selecting ideas
1. Implementing ideas
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
6
The Deming Cycle
Act
Plan
Study
Do
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
7
Juran’s Improvement Program
•
•
•
•
•
•
Proof of the need
Project identification
Organization for breakthrough
Diagnostic journey
Remedial journey
Holding the gains
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
8
Bethesda Hospital Model
Start
Generate solutions
Review
current
situation
Plan
Do
Describe
process
no
Check
Explore
cause theories
no
Improvement?
Collect and
analyze data
Improvement?
yes
yes
Act
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
9
Crosby Quality Improvement
Program
1. Management
commitment
2. Quality improvement
team
3. Quality measurement
4. Cost of quality
evaluation
5. Quality awareness
6. Corrective action
7. Zero defect committee
8. Supervisor training
9. Zero defects day
10. Goal setting
11. Error cause removal
12. Recognition
13. Quality councils
14. Do it over again
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
10
Creative Problem Solving
• Mess Finding – identify symptoms
• Fact Finding – gather data; operational
definitions
• Problem Finding – find the root cause
• Idea Finding – brainstorming
• Solution Finding – evaluate ideas and
proposals
• Implementation – make the solution work
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
11
Six-Sigma Quality
• Ensuring that process variation is half the
design tolerance (Cp = 2.0) while allowing
the mean to shift as much as 1.5 standard
deviations.
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
12
Six-Sigma Metrics
• Defects per unit (DPU) = number of
defects discovered  number of units
produced
• Defects per million opportunities
(dpmo) = DPU  1,000,000 
opportunities for error
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
13
k-Sigma Quality Levels
• Six sigma results in at most 3.4 defects per
million opportunities
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
14
Six-Sigma Implementation
1.
2.
3.
4.
Emphasize dpmo as a standard metric
Provide extensive training
Focus on on corporate sponsor support
Create qualified process improvement
experts
5. Ensure identification of appropriate
metrics
6. Set stretch objectives
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
15
GE’s Six-Sigma
Problem Solving Approach
1.
2.
3.
4.
5.
Define
Measure
Analyze
Improve
Control
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
16
Tools for Six-Sigma
and Quality Improvement
•
•
•
•
•
•
•
Elementary statistics
Advanced statistics
Product design and reliability
Measurement
Process control
Process improvement
Implementation and teamwork
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
17
The Seven QC Tools
1.
2.
3.
4.
5.
6.
7.
Flowcharts
Check sheets
Histograms
Cause-and-effect diagrams
Pareto diagrams
Scatter diagrams
Control charts
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
18
Flowcharts
• Shows unexpected complexity, problem
areas, redundancy, unnecessary loops, and
where simplification may be possible
• Compares and contrasts actual versus ideal
flow of a process
• Allows a team to reach agreement on
process steps and identify activities that
may impact performance
• Serves as a training tool
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
19
Run Chart
• Monitors performance of one or more
processes over time to detect trends, shifts,
or cycles
• Allows a team to compare performance
before and after implementation of a
solution to measure its impact
• Focuses attention on truly vital changes in
the process
*
*
* *
*
*
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
*
20
Control Chart
• Focuses attention on detecting and
monitoring process variation over time
• Distinguishes special from common causes
of variation
• Serves as a tool for on-going control
• Provides a common language for discussion
process performance
*
*
* *
*
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
*
*
21
Check Sheet
• Creates easy-to-understand data
• Builds, with each observation, a clearer
picture of the facts
• Forces agreement o the definition of each
condition or event of interest
• Makes patterns in the data become
obvious quickly
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
xx
xxxxxx
x
22
Pareto Diagram
• Helps a team focus on causes that have the
greatest impact
• Displays the relative importance of
problems in a simple visual format
• Helps prevent “shifting the problem” where
the solution removes some causes but
worsens others
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
23
Histogram
• Displays large amounts of data that are
difficult to interpret in tabular form
• Shows centering, variation, and shape
• Illustrates the underlying distribution of the
data
• Provides useful information for predicting
future performance
• Helps to answer the question “Is the process
capable of meeting requirements?
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
24
Cause and Effect Diagram
• Enables a team to focus on the content of a
problem, not on the history of the problem or
differing personal interests of team members
• Creates a snapshot of collective knowledge and
consensus of a team; builds support for solutions
• Focuses the team on causes, not symptoms
Effect
Cause
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
25
Scatter Diagram
• Supplies the data to confirm a hypothesis
that two variables are related
• Provides both a visual and statistical means
to test the strength of a relationship
• Provides a good follow-up to cause and
effect diagrams
*
*
*
* *
*
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
26
Poka-Yoke (Mistake-Proofing)
• An approach for mistake-proofing processes
using automatic devices or methods to avoid
simple human or machine error, such as
forgetfulness, misunderstanding, errors in
identification, lack of experience,
absentmindedness, delays,
or malfunctions
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
27
Poka-Yoke Examples
(from John Grout’s Poka-Yoke Page)
THE MANAGEMENT AND CONTROL OF QUALITY, 5e, © 2002 South-Western/Thomson LearningTM
28