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Transcript of Quality Assurance,
PTTE 434 - Lecture 1Quality Assurance,Organization & Management
Jim Wixson, CVS, [email protected]
(208) 520-2296 (mobile)(425) 385-8028 (Everett Apartment)
(425) 294-6947 (Boeing Office)
2
Lecture 1 - Objectives Learn the five definitions of quality Learn about some of the various quality “movements. Understand the concept of “Cost of Poor Quality.” Understand the concept of “Continuous Improvement.” Talk about some of the continuous improvement leaders and
tools. Learn about the importance of defining the problem well
before trying to solve it.
3
Garvin’s Five Definitions of Quality Transcendent Definition (Relative Quality): Quality is
universally recognizable; it is related to a comparison of features and characteristics of products.
Product-Based: Quality is a precise and measurable variable. Differences in quality reflect differences in quantity of some product attribute.
User-Based Definition: Quality is “fitness for intended use.”
4
Garvin’s Five Definitions of Quality (Cont’d) Manufacturing-Based Definition: Quality is “conformance to
specifications.” Value-Based Definition: Quality is defined in terms of costs
and prices. A quality product is one that provides performance at an acceptable price or conformance at an acceptable costs.
5
Quality Revolution or Quality Confusion?
6
Juran’s Approach
Balanced approach using managerial, statistical, and technological concepts of quality
Operational Framework: Quality Planning, Control, and Improvement
7
W. Edwards Deming
Broad Systems view of quality 14 points focused on four parts:
systems approach statistical variation nature and scope of knowledge psychology and understanding of human
behavior
8
A. V. Feigenbaum
Emphasized “Total Quality Control” throughout all functions of the organization.
Total Quality Control means both planning and control.
Provide technical and managerial procedures to ensure customer satisfaction and an economical cost of quality.
9
Philip Crosby
Defined quality as: Conformance to requirements.
The only performance standard is ZERO DEFECTS.
All levels of employees can be motivated, but, they need the right tools.
10
Crosby’s Four Absolutes of Quality Management
Quality is defined as conformance to requirements, not as 'goodness' nor 'elegance'.
The system for causing quality is prevention, not appraisal.
The performance standard must be Zero Defects, not 'that's close enough'.
The measurement of quality is the Price of Non-conformance, not indices.
11
Kaoru Ishikawa
Showed the Japanese how to integrate the many tools of quality, especially the simpler tools.
Basic 7 Tools: Histograms, Pareto Charts, Cause and Effect Diagrams, Run Charts, Scatter Diagrams, Flow Charts, Control Charts
12
Six Sigma?
13
Show Film
Carving a Career in Quality, Phillip Cosby and Assoc., 25 min.
14
It can’t be done!
“Management wants us to add on these quality activities to our regular duties without giving us the additional time [to accomplish them] -- it can’t be done!”
Discussion - How can it be done? Has your employer implemented any quality
improvement programs? How was it done?
15
Quality? - Convincing Management
Loss of production Loss of customers Loss of business Loss of jobs Class - Can you list some more reasons?
16
Hidden costs of poor quality
Reprocessing
Rejects Sorting InspectionCustomer returns
Warranty expenses
Downgrading of product
Lost salesProcess downtimeExtra inventoryLost discounts
Damaged goods
Premium freight costs
Customer allowances
Overtime to correct errorsLoss of good will
Paperwork errorsDelays
Obsolete inventory
Incorrect orders shipped
Extra process capacity
Competitor
Competitor
Competitor
17
Quality? - Convincing Management
Quality is no longer just a technical issue, it is a business issue.
In order for a quality program to succeed, top management must be involved and committed to its success.
A company’s success is directly related to management’s commitment to quality.
18
Opportunity Cost of AttritionD
olla
rs (
000s
)
Nu
mb
er o
f H
ou
seh
old
s
Quarters
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
50,000
0
100,000
150,000
300,000
200,000
250,000
1Q
$26,000
2Q
$28,000
3Q
$27,000
4Q
$28,500
Annual Avg. profit lost (000s)
Households defecting
120,000 124,000 122,500125,000
19
Optimum Cost of Quality
Quality of Conformance %
Co
st p
er G
oo
d U
nit
of
Pro
du
ct
1000
Total quality costs per good unit
of product
Failure costs
Costs of appraisal plus prevention
(Perfection)(No quality)
Optimum cost
20
Two Components of QualityManufacturing Industries Service Industries
Product Features
Performance AccuracyReliability Timeliness
Durability Completeness
Ease of Use Friendliness and Courtesy
Serviceability Anticipating Customer Needs
Aesthetics Knowledge of Server
Availability of Options andExpandability
Appearance of Facility andPersonnel
Reputation Reputation
Freedom from Deficiencies
Product free of defects anderrors at delivery, during use,and during servicing
Service free of errors duringoriginal and future servicetransactions
All processes free of reworkloops, redundancy, and otherwaste
All processes free of reworkloops, redundancy, and otherwaste
21
Quality Progress
Market
research
Customer
service
Marketin
g,
administrativ
e
support
Inspecti
on
Test
Production
Process
Control
Operations
planning
Specifica
tion
Product
development
and design
Market
research
Purchasin
g
Suppliers
Wholesaling
Retailing
Use
Feedback
22
Little Q and Big Q
Topic Content of Little Q(internal view)
Content of Big Q(external view)
Products Manufactured Goods All products, goods, andservice whether for sale, or not
Processes Processes directly relatedto manufacture of goods
All processes; manufacturingsupport; business, etc.
Industries Manufacturing All industries; manufacturing;service, government, etc.whether for profit or not
23
Continuous ImprovementI
Am
Responsible
for Quality
As a
Good Process Owner or User
I will:
As a
Good Supplier
I will:
As a
Good Customer
I will:
1. Agree on and document my requirements with my supplier.
2. Return defective inputs to my supplier promptly and tactfully.
3. Feedback input quality data to my supplier.
1. Understand my customer requirements, and agree on and document my deliverables.
2. Reduce defects and variations in my output.
3. Measure my output quality from my customer’s perspective.
1. Learn to apply the tools of quality - teach others.
2. Continuously improve my process - reduce defects, cycle time, and know benchmarks.
3. Document and display my process, defect levels, and CI projects.
Requirements and feedback
My input
My supplier
My customer
Requirements and feedback
My output
24
Competitive Standing
25
Attribute Comparison - Radar Graph
0
20
40
60
80
100
120
140
160
180
Safety
Performance
Quality
Field serviceEase of use
Company image
Plant service
Company X Competitor A Competitor B
26
Maintain Status quo Leverage competitive strength
Assign little or no priority on action.
Add resources to achieve improvement
Performance - Satisfaction Map
200
60
40
80
100
17.5 35 52.5 70
Importance
Per
form
ance
(%
sat
isfi
ed)
Product
Sales
Repairs
Billing
27
Convincing upper managementReturn on assets (ROA) = Profit margin x Asset turnover
Assume COPQ* = 10% of sales revenue
Profit margin = 7%
Asset turnover = 3.0
=> ROA = 7% x 3.0 =21%
Assume COPQ reduced to 6% of sales revenue
=> Profit margin = 7% + (10% - 6%) = 11%
Asset turnover = 3.0
=> ROA = 11% x 3.0 = 33%
A 4% reduction in COPQ results in a 12% increase in ROA!!
*Cost of Poor Quality
28
Convincing upper management
Estimate the size of quality related losses. Identify ways of improving quality. Estimate the savings and other benefits. Calculate return on investment (ROI) Use a successful case history to justify a
broader program. If all else fails, take pictures of waste and/or
hazards (EIMCO example).
29
Are Quality Approaches Influenced By Culture?
Quality Approaches are Influence by Culture
The US approach has historically been
command-and-control oriented.
The Japanese approach is based on
an ethic of consistency and emphasis on
reduction of waste.
The Europeans have adopted broad
standards that can be adapted to the
diverse nation states of the EC.
30
National and International Quality Awards Malcolm Baldrige National Quality Award Deming Prize European Quality Award Shingo Prize
The US approach has historically been
command-and-control oriented.
31
The Malcolm Baldrige National Quality Award
Malcolm Baldrige National Quality Award The award is open to small (less than 500 employees)
and large firms (more than 500 employees) in the manufacturing and service sectors.
There can be only two winners per category each year. That limits the number of yearly awards to six.
32
The Malcolm Baldrige National Quality Award
The President of the United States traditionally presents the Awards at a special ceremony in Washington, DC. Awards are made annually to recognize U.S. organizations for performance excellence. The Award eligibility categories are:
manufacturing businesses service businesses small businesses education organizations health care organizations
Recipients are expected to share information about their successful performance strategies with other U.S. organizations.
33
The Malcolm Baldrige National Quality Award
The Award is named for Malcolm Baldrige, who served as Secretary of Commerce from 1981 until his tragic death in a rodeo accident in 1987. His managerial excellence contributed to long-term improvement in efficiency and effectiveness of government.
34
The Malcolm Baldrige National Quality Award
The Malcolm Baldrige National Quality Award was created by Public Law 100-107, signed into law on August 20, 1987.
The Award Program, responsive to the purposes of Public Law 100-107, led to the creation of a new public-private partnership.
Principal support for the program comes from the Foundation for the Malcolm Baldrige National Quality Award, established in 1988.
35
The Malcolm Baldrige National Quality Award
Key Characteristics of the MBNQA Criteria The criteria focus on business results.
Companies must show outstanding results in a variety of areas to win.
The Baldrige criteria are nonprescriptive and adaptive. Although the focus on the Baldrige award is on results, the means for obtaining these results are not prescribed.
36
The Malcolm Baldrige National Quality Award
Key Characteristics of the MBNQA (cont.) The criteria support company-wide alignment
of goals and processes. The criteria permit goal-based diagnosis. The criteria and scoring guidelines provide
assessment dimensions.
37
MBNQA Criteria
The Criteria are designed to help organizations use an integrated approach to organizational performance management that results in: delivery of ever-improving value to customers, contributing to marketplace success improvement of overall organizational effectiveness and
capabilities organizational and personal learning
38
MBNQA Criteria
The Criteria are the basis for organizational self-assessments,for making Awards, and for giving feedback to applicants. In addition, the Criteria have three important roles in strengthening U.S. competitiveness: to help improve organizational performance practices,
capabilities, and results to facilitate communication and sharing of best practices
information among U.S. organizations of all types to serve as a working tool for understanding and managing
performance and for guiding organizational planning and opportunities for learning
39
The Malcolm Baldrige National Quality Award
Baldrige Award Framework
4Information and analysis
3Customer andmarket focus
6Process
management
1Leadership
7Businessresults
2Strategic planning
5HR develop. &management
Customer and Market Focused Strategy and Action Plans
40
In the second phase, Board of Examiners to conduct a rigorous evaluation of an organization's performance management system and the results of its processes.
The first phase of the Award cycle is to establish that the applicant meets the eligibility requirements. Applicants submit an Eligibility Certification Package certifying that the organization is eligible to apply for the Award.
The third phase of the Award cycle involves the review of the application package. Applications are reviewed and evaluated by members of the Board of Examiners, all of whom adhere to strict rules regarding conflict of interest. The review is conducted in three stages:
Stage 1 - Independent ReviewStage 2 - Consensus ReviewStage 3 - Site Visit Review
41
The Malcolm Baldrige National Quality Award
Being a Baldrige Examiner Appointment to the board of Trustees for the
MBNQA Board of Examiners is a very prestigious designation.
Examiners are unpaid volunteers, and must be willing to give up approximately 10% of their year to serve as an examiner.
42
The Malcolm Baldrige National Quality Award
For more information on the Malcolm Baldridge National Quality Award, visit:
http://www.quality.nist.gov/
43
Quality Improvement: The Japanese Way
Deming Prize The Deming Prize for quality was established
in 1951 by the Japanese Union of Scientists and Engineers (JUSE).
The Deming Prize is much more focused on processes than is the Baldrige.
The Japanese approach is based
on an ethic of consistency and
emphasis on reduction of waste.
44
What is the Deming Prize?
The Deming Application Prize Given to companies or divisions of companies that have achieved distinctive performance improvement through the application of TQM in a designated year.
The Deming Prize for IndividualsGiven to individuals who have made outstanding contributions to the study of TQM or statistical methods used for TQM, or individuals who have made outstanding contributions in the dissemination of TQM.
The Quality Control Award for Operations Business UnitsGiven to operations business units of a company that have achieved distinctive performance improvement through the application of quality control/management in the pursuit of TQM in a designated year.
45
The Deming Prize
For more information on the Deming Prize visit:
http://www.deming.org/demingprize/
46
Other Japanese Contributions to Quality Thought Lean Manufacturing (Toyota Production
System) Lean is a method of systematically eliminating waste in
a production system. Lean dramatically reduces cycle time. Lean focuses on the company’s “value stream” to
identify wasted movement, wasted time, wasted inventory, and wasted space.
Lean has been adopted by many US manufacturers and other firms and has aided them in achieving dramatic improvements in operations
47
Other Japanese Contributions to Quality Thought - 5 S’s
Other Japanese Contributions to Quality (cont.) The Five S’s. The five Ss are a sequential process
that companies follow to literally “clean up their acts.” The Ss are:
Seri (Sort): organizing by getting rid of the unnecessary.
Seiton (set in order): neatness that is achieved by straightening offices and work areas.
Siso (Shine): cleaning plant and equipment to eliminate dirtiness that can hide or obscure problems.
Seiketsu (Standardize): standardizing locations for tools and other materials.
Shetsuke (Sustain): discipline in maintaining the prior four Ss.
48
Other Japanese Contributions to Quality Thought
Other Japanese Contributions to Quality (cont.) Quality Circles
Are natural work teams made up of workers that are empowered to improve processes they use.
Total Productive Maintenance (TPM) The idea behind this concept is that the worst
condition a machine should ever by is on the day you purchase it.
49
Shingo Prize for Excellence in Manufacturing
Named for Japanese industrial engineer Shigeo Shingo who distinguished himself as one of the world’s leading experts in improving manufacturing processes.
The Prize was established in 1988 to promote awareness of Lean manufacturing concepts
Recognizes companies in the United States, Canada, and Mexico that achieve world-class manufacturing status.
50
Shingo Prize for Excellence in Manufacturing
The Shingo Prize recognizes organizations and research that is consistent with its mission and model with two types of prizes:
Business Prize—promotes use of world-class manufacturing strategies and practices to achieve world-class results.
Research Prize—promotes research and writing regarding new knowledge and understanding of manufacturing processes.
Business Week referred to the Shingo Prize as the “Nobel prize of manufacturing,” because it establishes the standard for world-class excellence.
51
Shingo Prize for Excellence in Manufacturing
For more information on the Shigo Prize visit:
http://www.shingoprize.org/AboutUs/default.htm
http://www.partnersusu.org/
52
Quality Improvement: The European Way
ISO 9000 Is the European standard for quality that has been
expanded worldwide. The ISO 9000 family is primarily concerned with
"quality management". This means what the organization does to fulfil: the customer's quality requirements, and applicable
regulatory requirements, while aiming to enhance customer satisfaction, and achieve continual improvement of its performance The Europeans have
adopted broad standards that can be adapted to the
diverse nation states of the EC.
53
Quality Improvement: The European Way
The ISO 14000 family is primarily concerned with "environmental management". This means what the organization does to: minimize harmful effects on the environment
caused by its activities, and to achieve continual improvement of its
environmental performance.
54
ISO 9000 and 14000
ISO 9000 and ISO 14000 are known as generic management system standards.
Generic means that the same standards can be applied to any organization, large or small, whatever its product - including whether its "product" is actually a service - in any sector of activity, and whether it is a business enterprise, a public administration, or a government department.
Management system refers to what the organization does to manage its processes, or activities in order that the products or services that it produces meet the objectives it has set itself, such as the following:
satisfying the customer's quality requirements,
complying to regulations, or
meeting environmental objectives.
55
ISO 9000 and 14000
For more information on the ISO 9000 and ISO 14000 visit:
http://www.iso.ch/iso/en/iso9000-14000/index.html
56
European Quality Award
European Foundation for Quality Management (EFQM) was founded in 1988 by the Presidents of 14 major European companies
First European Quality Award issued in 1992
Endorsed by the EU Commission
Network has more than 700 members
Formed the European framework for quality improvement along the lines of the Malcolm Baldrige Model in the USA and the Deming Prize in Japan. The Europeans have
adopted broad standards that can be adapted to the
diverse nation states of the EC.
57
European Quality Award
Europe's most prestigious Award for organizational Excellence
Award levels are: Award Winner Prize Winners Finalists Recognized for Excellence
58
European Quality Award Prize Winner categories consist of :
Leadership and constancy of purpose
Customer focus
Corporate social responsibility
People development and involvement
Results orientation
Management by processes and facts
Continuous learning, innovation and improvement
Partnership development
59
European Quality Award
For more information on the European Quality Award visit:
http://www.efqm.org/model_awards/eqa/intro.asp
60
Contributions of Various Disciplines
Finance: Measuring the cost of poor quality Industrial Engineering: Design of integrated
systems, measurement, problem solving, work analysis
Information Technology: Measurement, analysis, and reporting on quality
Marketing Research: Competitive standing on quality, understanding customer desires
Operations Management: Management of integrated systems
61
Operations research: Analyzing product design alternatives for optimization
Organizational Behavior: Understanding quality culture, making teams effective.
Organizational Effectiveness: Satisfying the needs of both internal and external customers.
Contributions of Various Disciplines (Cont’d)
62
Contributions of Various Disciplines (Cont’d)
Strategic Planning: Quality as a means of achieving a unique competitive advantage.
Systems Engineering: Translating customer needs into product features and process features
Value Engineering: Analysis of essential functions needed by customer to find the lowest cost way of providing these functions that meet quality, reliability, and performance requirements.
63
Systems Dynamics
Most process improvement efforts rely on breaking problems down into smaller, more manageable, components.
This “reductionist” approach sometimes fails to recognize that the problem is greater than the sum of its parts.
A “systems thinking” approach to identify interactions between activities and the unintended consequences that can arise from well-intended corrective actions.
64
How SD can facilitate the Improvement Efforts
SD provides a visual model of the system under study.
Changes to the system can be made easily and quickly analyzed
Repeated iteration of a SD model can optimize the system under study
65
Approach for Quality Improvement Projects
Get a champion Prove the need Identify Projects Organize teams Perform the study, or Kaisan Document recommendations Perform a pilot project Document results Expand to entire organization
66
Carrying out the project
Verify project need and mission Diagnose the causes Provide a remedy and prove its effectiveness Deal with resistance to change Institute controls to hold the gains
67
Intro to Six Sigma
Six Sigma Capability: Extremely small variation in the process mean compared to the range of the specification limits.
Even if process mean shifts by 1.5 sigma => no more than 3.4 parts per million fall out of the specification limit.
Key focus: Y=f(X1…Xn)
68
Breakthrough Improvement
Verify the project need (Six Define) Diagnose the Causes (Six Measure and
Analyze) Provide a remedy and prove its effectiveness
(Six Improve) Deal with resistance to Change (Six
Improve) Institute controls to hold the gains (Six
Control)
69
Define the ProblemDefine the Problem
MeasureMeasure
AnalyzeAnalyze
ImproveImprove
ControlControl
End
A) Identify what the customer wants. B) Organize an improvement team. C) Create a process flow chart - (SIPOC)
A) Identify what the customer wants. B) Organize an improvement team. C) Create a process flow chart - (SIPOC)
A) Select “Critical to Quality Characteristic” metrics. B) Define Performance Standards. C) Validate the measurement System. D) Establish baseline performance in terms of Sigma Capability - Defects per
Million Opportunities.
A) Select “Critical to Quality Characteristic” metrics. B) Define Performance Standards. C) Validate the measurement System. D) Establish baseline performance in terms of Sigma Capability - Defects per
Million Opportunities.
A) Identify significant characteristics and establish process capability. B) Define performance targets for significant characteristics. C) Identify root cause of process variation.
A) Identify significant characteristics and establish process capability. B) Define performance targets for significant characteristics. C) Identify root cause of process variation.
A) Identify and evaluate potential solutions. B) Implement short-term countermeasures. C) Implement long term corrective actions. D) Identify systemic indirect effects and unintended consequences of
improvement ideas. E) Establish operating tolerances for new process.
A) Identify and evaluate potential solutions. B) Implement short-term countermeasures. C) Implement long term corrective actions. D) Identify systemic indirect effects and unintended consequences of
improvement ideas. E) Establish operating tolerances for new process.
A) Verify corrective actions and validate new measurement systems. B) Determine process capability. C) Establish and implement control plan.
A) Verify corrective actions and validate new measurement systems. B) Determine process capability. C) Establish and implement control plan.
Move on to next highest priority process. Move on to next highest priority process.
Six Sigma Process - Click Here
70
Value Engineering
Value Engineering (VE) is an intensive, interdisciplinary problem solving activity that focuses on improving the value of the functions that are required to accomplish the goal, or objective of any product, process, service, or organization.
VALUE METHODOLOGY“The systematic application of recognized techniques which identify the functions of the product or service, establish the worth of those functions, and provide the necessary functions to meet the required performance at the lowest overall cost.”
*John M. Bryant, VM Standard, Society of American Value Engineers, Oct. 1998
71
Value Engineering/Value Analysis - Why is it important?
Last 3 years, 2.7 million manufacturing jobs left the U.S.
The U.S. is loosing the battle to foreign competition. Labor costs $12 to $30 per hour in U.S., less than $1
elsewhere. Fewer and fewer people will be required to produce
the world’s goods. Lean and Six Sigma alone are not enough!
72
Competitive Advantage
Quality is defined as “conformance to specification.”
Value is defined as:Function
Cost
You can’t have one without the other!
Competitive Advantage = Quality + Value
73
Six Step Value Engineering Job PlanInformation
PhaseInformation
Phase
Creativity Phase
Creativity Phase
Evaluation Phase
Evaluation Phase
Planning PhasePlanning Phase
Reporting Phase
Reporting Phase
Implementation Phase
Implementation Phase
Clearly identify the problem(s) to be solved, and gather information on the background, functions and requirements of the product, process, or system.
Clearly identify the problem(s) to be solved, and gather information on the background, functions and requirements of the product, process, or system.
Brainstorm ideas on how to improve the high cost, broken, or inadequately performed key functions.
Brainstorm ideas on how to improve the high cost, broken, or inadequately performed key functions.
Screen ideas for acceptance, score remaining ideas on a scale and group ideas into categories. Develop design scenarios, and selection criteria. Rate and rank ideas.
Screen ideas for acceptance, score remaining ideas on a scale and group ideas into categories. Develop design scenarios, and selection criteria. Rate and rank ideas.
Plan how to sell ideas to management, identify key recommendations, plan management presentation.
Plan how to sell ideas to management, identify key recommendations, plan management presentation.
Give oral presentation to management, or develop written report.
Give oral presentation to management, or develop written report.
Get management approval for go-ahead, make management plan, make assignments, implement, follow-up.
Get management approval for go-ahead, make management plan, make assignments, implement, follow-up.
74
Mapping VE to 6
Information Phase
Information Phase
Creativity PhaseCreativity Phase
Evaluation Phase
Evaluation Phase
Planning PhasePlanning Phase
Reporting PhaseReporting Phase
Implementation Phase
Implementation Phase
Define the ProblemDefine the Problem
MeasureMeasure
AnalyzeAnalyze
ImproveImprove
ControlControl
VA/VE 6
75
Vilfredo Pareto
Vilfredo Pareto (1848-1923) was an Italian economist and a political sociologist. He devised the law of the trivial many and the critical few, known as the 80:20 rule.
Pareto’s Law states that in many business activities 80% of the potential value can be achieved from just 20% of the effort. The remaining 80% of effort shows relatively little return.
76
Defining the Problem - Pareto Analysis
Quality Improvement Example
Solder Defects
78
Solder Defects - Pareto Analysis
Solder Defects
0
50
100
150
200
250
300
350
Defect Type
Occ
ure
nce
of D
efec
ts
0%
20%
40%
60%
80%
100%
120%
Cu
mla
tive
Per
cen
t of D
efec
ts
Series2 297 73 62 62 45 21
Series1 53% 66% 77% 88% 96% 100%
Insufficient Solder
Blow Holes Unwetted Unsoldered Shorts Pinholes
79
Ishikawa or Fishbone Diagram
Back to CauseCatagories
Print Color Diagram
Back to Problem
Back to SpecificCauses
Solder Defects
Temp. control error
MaintenanceAmount
Controller
Low-high solids
Exhaust
Orientation
Metallurgy
Geometry
ActivityMovement
Specific gravity
Contaminated leads
Placement
Contamination
Temperature
TemperatureValidity
Interpretation
Void in pth
Weight Alloy
Dross
Components MachinesFlux
PWC Spec Solder
Back to Main Menu
preheat
Time
Orientation
Warped
Outgassingt
80
Process Data
1 2 3 4 5 6 7 8 9 10 11 12
350
300
250
200
Te m
per
a tu
re o F
Seconds
Region of cold solder joints
Region of heat overload on P.C.B.A.
81
Conclusions
Either raise solder temperature, or slow down the conveyor.
A previous test years ago had been conducted at a higher temperature, but, resulted in “reflow of tin under the solder mask.”
A trial was conducted at a higher temperature yielding satisfactory results and broke the resistance to change.
82
Don’t jump to solution!
An apparel manufacturing company detected a problem with it’s “fuseable” lining.
Many customer returns Lining falling off after a few washings Solution: “We need a new brand of lining.
Our current brand is defective!”
83
Don’t jump to solution! - DOE Fusible Lining Example
Fusible Lining Experiment
0
1
2
3
4
5
6
7
8
9
10
160 170 180 190 200 210 220 230 240 250 260
Temp. deg C.
Su
ccesses
a b Current Expected Poly. (Expected)
A
B
Current
?
Expected
84
Sporadic v.s. Chronic Problems
Sporadic problems are dramatic and require immediate attention.
Chronic problems are not dramatic, they occur over a long period of time.
Chronic problems are difficult to solve. Chronic problems are “accepted as
inevitable.”
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Sporadic v.s. Chronic Problems
Sporadic problems are solved by fixing the control process.
Chronic problems are solved using process improvement techniques such as Value Engineering and/or Six Sigma.
Value Engineering may be applied to sporadic problems as well, e.g., Boeing 737/757 elevator feel computer problem.
86
Sporadic and chronic quality problems
Lo
ss d
ue
to d
efec
ts
Time
Sporadic departure from historic level
Historic level
Improved level
The difference between historic and improved levels is caused by a chronic disease that can be eliminated economically through process improvement techniques.