Quality Attributes; Product specific, Organization Specific
Standards of Quality; ISO, TQM, Six Sigma
Quality Attributes
• Quality attributes set is a way to represent customer quality requirements
• Ask your current and prospective customers about their definition of quality
• Develop a quality assurance program based on the requirements of your customers
Product-Specific Attributes
• Ease of use• Documentation• Defect tolerance• Defect frequency• Defect impact• Packaging• Price versus reliability• Performance
Organization-Specific Attributes
• Service and support• Internal processes
Achieving High Levels of Software Quality - 1
• Enterprise-wide quality programs• Quality awareness and training methods• Quality standards and guidelines• Quality analysis methods• Quality measurement methods• Defect prevention methods• Non-test defect removal methods
Achieving High Levels of Software Quality - 2
• Testing methods• User-satisfaction methods• Post-release quality control
Quality Assurance Organizations
• No quality assurance 60%• Token quality assurance 20%• Passive quality assurance 15%• Active quality assurance 5%
Best in Class Quality Results - 1
• Quality measurements• Defect prevention• Defect and quality estimation automation• Defect tracking automation• Complexity analysis tools• Test coverage analysis tools• Formal inspections
Best in Class Quality Results - 2
• Formal testing by test specialists• Formal quality assurance group• Executive and managerial understanding of
quality
Two Components ofSoftware Quality Improvement
• Reductions in total defect potentials using methods of defect prevention
• Improvements in cumulative removal efficiency levels
Categories of Software Defects
• Errors of commission: something wrong is done
• Errors of omission: something left out by accident
• Errors of clarity and ambiguity: different interpretations
• Errors of speed and capacity
Software Defect Prevention Req.
Defects Design Defects
Code Defects
Document Defects
Perf. Defects
JAD
Excellent
Good
N/A
Fair
Poor
Prototypes
Excellent
Excellent
Fair
N/A
Excellent
Structured Methods
Fair
Good
Excellent
Fair
Fair
CASE Tools
Fair
Good
Fair
Fair
Fair
Blueprints / Reusable Code
Excellent
Excellent
Excellent
Excellent
Good
QFD
Good
Excellent
Fair
Poor
Good
Joint Application Development
• Users are active participants in the requirements sessions
• Both client and MIS sides agree on uninterrupted time commitments
• JAD-based requirements are more “complete” versus the traditional requirements
Quality Function Deployment
• QFD is a very formal, structured group activity involving clients and development personnel
• During QFD sessions, user’s quality criteria are exhaustively enumerated and defined. This is followed by the product’s quality response to these requirements
Project Management Approaches and Poor Software Quality
• Exact opposite of the project management approaches correlating with high software quality
SQA Group’s Activities - 1
• Preparation of an SQA plan for a project– Evaluations to be performed– Audits and reviews to be performed– Standards that are applicable to the project– Procedures for error reporting and tracking– Documents to be produced by the SQA group– Amount of feedback provided to the software
project team
SQA Group’s Activities - 2
• Participation in the development of the project’s software process description
• Review of software engineering activities to verify compliance with the defined software process
• Audit of designed software work products to verify compliance with those defined as part of the software process
SQA Group’s Activities - 3
• Ensure that deviations in software work and work products are documented and handled according to a documented procedure
• Record any noncompliance and reports to senior management
Costs of Software Quality - 1
• Defects prevention costs• User satisfaction optimization costs• Data quality defect prevention costs• Data quality defect removal costs• Quality awareness/training costs• Non-test defect removal costs• Testing defect removal costs
Costs of Software Quality - 2
• Post-release customer support costs• Litigation and damage award costs• Quality savings from reduced scrap/rework• Quality savings from reduced user downtime• Quality value from reduced time-to-market
intervals
Costs of Software Quality - 3
• Quality value from enhanced competitiveness• Quality value from enhanced employee
morale• Quality return on investment
Cost Per Defect Hazards
• Test cases must be created whether there are many bugs, only a few, or none at all
• Test cases must be run whether there are any bugs or not, although tests will be run more often for buggy software
• During testing, programmers are waiting (and getting paid) for bugs to be found
Standards for Quality Management System
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Fitness forConsumer UseFitness forConsumer Use
Producer’s PerspectiveProducer’s Perspective Consumer’s PerspectiveConsumer’s Perspective
Quality of ConformanceQuality of Conformance
• Conformance to specifications
• Cost
Quality of DesignQuality of Design
• Quality characteristics• Price
MarketingMarketingProductionProduction
Meaning of Quality Meaning of Quality
Meaning of Quality
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TQM and…
• … Partnering– a relationship between a company and its
supplier based on mutual quality standards• … Customers
– system must measure customer satisfaction• … Information Technology
– infrastructure of hardware, networks, and software necessary to support a quality program
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Quality Improvement and Role of Employees
• Participative problem solving– employees involved in
quality management – every employee has
undergone extensive training to provide quality service to Disney’s guests
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PresentationImplementationMonitoring
SolutionProblem results
Problem AnalysisCause and effectData collection and analysis
Problem IdentificationList alternativesConsensusBrainstorming
TrainingGroup processesData collectionProblem analysis
Organization8-10 membersSame areaSupervisor/moderator
Quality Circle
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Strategic Implications of TQM
• Strong leadership• Goals, vision, or mission• Operational plans and policies• Mechanism for feedback
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Six Sigma
• A process for developing and delivering near perfect products and services
• Measure of how much a process deviates from perfection
• 3.4 defects per million opportunities• Champion
– an executive responsible for project success
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Black Belts and Green Belts
• Black Belt– project leader
• Master Black Belt– a teacher and mentor
for Black Belts
• Green Belts– project team members
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3.4 DPMO3.4 DPMO
67,000 DPMOcost = 25% of sales
67,000 DPMOcost = 25% of sales
DEFINEDEFINE CONTROLCONTROLIMPROVEIMPROVEANALYZEANALYZEMEASUREMEASURE
Six Sigma: DMAIC
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TQM in Service Companies
• Principles of TQM apply equally well to services and manufacturing
• Services and manufacturing companies have similar inputs but different processes and outputs
• Services tend to be labor intensive• Service defects are not always easy to
measure because service output is not usually a tangible item
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Quality Attributes in Service
• Benchmark– “best” level of quality
achievement one company or companies seek to achieve
• Timeliness– how quickly a service is
provided“quickest, friendliest, most
accurate service available.”
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Cost of Quality
• Cost of Achieving Good Quality– Prevention costs
• costs incurred during product design– Appraisal costs
• costs of measuring, testing, and analyzing• Cost of Poor Quality
– Internal failure costs• include scrap, rework, process failure, downtime, and
price reductions– External failure costs
• include complaints, returns, warranty claims, liability, and lost sales
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Prevention Costs• Quality planning costs
– costs of developing and implementing quality management program• Product-design costs
– costs of designing products with quality characteristics• Process costs
– costs expended to make sure productive process conforms to quality specifications
• Training costs– costs of developing and putting on quality training programs for
employees and management• Information costs
– costs of acquiring and maintaining data related to quality, and development of reports on quality performance
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Appraisal Costs
• Inspection and testing– costs of testing and inspecting materials, parts, and
product at various stages and at the end of a process• Test equipment costs
– costs of maintaining equipment used in testing quality characteristics of products
• Operator costs– costs of time spent by operators to gar data for testing
product quality, to make equipment adjustments to maintain quality, and to stop work to assess quality
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Internal Failure Costs
• Scrap costs– costs of poor-quality products
that must be discarded, including labor, material, and indirect costs
• Rework costs– costs of fixing defective
products to conform to quality specifications
• Process failure costs– costs of determining why
production process is producing poor-quality products
• Process downtime costs– costs of shutting down productive process to fix problem
• Price-downgrading costs– costs of discounting poor-quality products—that is, selling products as
“seconds”
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External Failure Costs
• Customer complaint costs– costs of investigating and
satisfactorily responding to a customer complaint resulting from a poor-quality product
• Product return costs– costs of handling and replacing
poor-quality products returned by customer
• Warranty claims costs– costs of complying with product
warranties
• Product liability costs– litigation costs resulting
from product liability and customer injury
• Lost sales costs– costs incurred because
customers are dissatisfied with poor quality products and do not make additional purchases
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Seven Quality Control Tools
• Pareto Analysis• Flow Chart• Check Sheet• Histogram
• Scatter Diagram• SPC Chart• Cause-and-Effect
Diagram
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NUMBER OFCAUSE DEFECTS PERCENTAGE
Poor design 80 64 %Wrong part dimensions 16 13Defective parts 12 10Incorrect machine calibration 7 6Operator errors 4 3Defective material 3 2Surface abrasions 3 2
125 100 %
Pareto Analysis
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Perc
ent f
rom
eac
h ca
use
Causes of poor quality
Mac
hine calib
rations
Defecti
ve par
ts
Wro
ng dim
ensio
ns
Poor Des
ign
Operato
r erro
rsDefe
ctive
mate
rials
Surfa
ce ab
rasio
ns
0
10
20
30
40
50
60
70(64)
(13)(10)
(6)(3) (2) (2)
Pareto Chart
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Flow Chart
Operation DecisionStart/ Finish
Start/ Finish
Operation
OperationOperation
Operation
Decision
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Check Sheet
COMPONENTS REPLACED BY LABTIME PERIOD: 22 Feb to 27 Feb 2002REPAIR TECHNICIAN: Bob
TV SET MODEL 1013
Integrated Circuits ||||Capacitors |||| |||| |||| |||| |||| ||Resistors ||Transformers ||||CommandsCRT |
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Histogram
0
5
10
15
20
1 2 6 13 10 16 19 17 12 16 2017 13 5 6 2 1
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Scatter Diagram
Y
X
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Control Chart
18
12
6
3
9
15
21
24
2 4 6 8 10 12 14 16
Sample number
Num
ber o
f def
ects
UCL = 23.35
LCL = 1.99
c = 12.67
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Cause-and-Effect Diagram
QualityProblemQualityProblem
Out of adjustment
Tooling problems
Old / worn
MachinesMachinesFaulty testing equipment
Incorrect specifications
Improper methods
MeasurementMeasurement
Poor supervision
Lack of concentration
Inadequate training
HumanHuman
Deficienciesin product design
Ineffective qualitymanagement
Poor process design
ProcessProcess
Inaccuratetemperature control
Dust and Dirt
EnvironmentEnvironment
Defective from vendor
Not to specifications
Material-handling problems
MaterialsMaterials
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Baldrige Award
• Created in 1987 to stimulate growth of quality management in the United States
• Categories– Leadership– Information and analysis– Strategic planning– Human resource– Focus– Process management– Business results– Customer and market focus
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ISO 9000
• A set of procedures and policies for international quality certification of suppliers
• Standards– ISO 9000:2000
• Quality Management Systems—Fundamentals and Vocabulary
• defines fundamental terms and definitions used in ISO 9000 family
• ISO 9001:2000– Quality Management Systems—
Requirements– standard to assess ability to
achieve customer satisfaction• ISO 9004:2000
– Quality Management Systems—Guidelines for Performance Improvements
– guidance to a company for continual improvement of its quality-management system
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Implications of ISO 9000 for U.S. Companies
• Many overseas companies will not do business with a supplier unless it has ISO 9000 certification
• ISO 9000 accreditation• ISO registrars• A total commitment to quality
is required throughout an organization
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