1. Quality Systems
Outline of the next three lectures:
• Quality Management Systems (QMS) for
software
• Statistical Process Control (SPC)
• Software Process Improvement (SPI) and
The software Capability Maturity Model
(CMM)
Software Quality CS2 1
Nathan Baddoo

2. Quality Management Systems (QMS)
for Software
Preview
•Historical perspective of QMS
•Elements of QMS
•Procedures in a quality management system
•Statistical Process Control (SPC) as an approach to
quality management
•The four principal aspects of a QMS for software
Software Quality CS2 2
Nathan Baddoo

3. Quality Management Systems (QMS)
for Software
Objectives
•Describe three historical perspectives of QMSs and
outline the work of the three quality 'gurus’.
•Describe the elements of a Quality Management
System
•Describe some of the procedures of a QMS
•Describe the concept of Statistical Process Control
•Describe the four principal components to a QMS for
software
Software Quality CS2 3
Nathan Baddoo

4. Quality Management Systems (QMS)
for Software
3 Historical Approaches to Quality
•Deming: Conformity and dependability approach
“Quality is satisfying the customer, not merely to meet his [sic]
expectations, but to exceed them”
•Juran: Fitness for purpose approach
“Quality is customer satisfaction or fitness for use”
•Crosby: ‘zero defects’ approach
“Quality is conformance to requirements”
“Quality is free”
Software Quality CS2 4
Nathan Baddoo

5. Quality Management Systems (QMS)
for Software
Deming’s conformity and dependability approach:
•Quality improvement lay in the ability to control and
manage systems and processes properly
•Statistical Process Control (SPC) for improving and
removing variation within processes
•Senior management should be responsible for taking
the lead to change processes and systems
•Employee participation in decision making
•Quality begins and ends with the customer
Software Quality CS2 5
Nathan Baddoo

6. Quality Management Systems (QMS)
for Software
Deming's 14 points for quality management
1. Constancy of purpose
2. A new philosophy
3. Cease dependence on inspections
4. End lowest tender contracts
5. Improve every process
6. Institute training on job
7. Institute leadership
8. Drive out fear
9. Break down barriers
10. Eliminate exhortations
11. Eliminate targets
12. Permit pride of workmanship
13. Encourage education
14. Create top management structures
Software Quality CS2 6
Nathan Baddoo

7. Quality Management Systems (QMS)
for Software
Juran’s fitness for use approach
•Quality is “customer satisfaction” or “fitness for use”
•Quality is managed by a trilogy of processes
Sporadic problems are detected through control processes
Chronic problems are addressed through improvement processes
Chronic problems are traceable to inadequate planning processes
•Statistical Process Control (SPS) for improving and
removing variation within processes
•Senior management responsibility and employee
participation
Software Quality CS2 7
Nathan Baddoo

8. Quality Management Systems (QMS)
for Software
Juran's ten points for quality management
1. Build awareness of need and opportunity for improvement
2. Set goals for improvement
3. Organise to reach goals
4. Provide training
5. Carry out projects to solve problems
6. Report progress
7. Give recognition
8. Communicate results
9. Keep score
10. Maintain momentum by making annual improvement part of the regular
process of the company
Software Quality CS2 8
Nathan Baddoo

9. Quality Management Systems (QMS)
for Software
Crosby’s ‘zero defects’ approach
•Identify and specify requirements correctly so that
they can be properly met
•Zero defects - get it right the first time
•Emphasis on prevention rather than after-the-fact
inspection
•Higher quality reduces cost and raises profits, hence
“quality is free”
•Emphasis on improving processes
Software Quality CS2 9
Nathan Baddoo

10. Quality Management Systems (QMS)
for Software
Crosby's 14 steps to quality improvement
1. Make it clear that management is committed to quality
2. Form quality improvement teams with each department committed
3. Determine where current and potential problems lie
4. Evaluate the cost of quality and explain its use as a tool
5. Raise the quality awareness and concerns of all employees
6. Take actions to correct problems identified
7. Establish a committee for zero defects programme
8. Train supervisors to actively carry out their role in quality improvement
9. Hold a 'zero defects' day for all employees to highlight the changes
10. Encourage individuals to establish improvement goals
11. Encourage communication with management about obstacles to
improvement
12. Recognise and appreciate participants
13. Encourage education
14. Create top management structures
Software Quality CS2 10
Nathan Baddoo

11. Quality Management Systems (QMS)
for Software
Elements of a QMS
•Organisational structure
•Responsibilities
•Procedures
•Processes
•Resources
Software Quality CS2 11
Nathan Baddoo

12. Quality Management Systems (QMS)
for Software
The procedures in a QMS
•Contract review
•Design control
•Documenting control
•Purchasing
•Customer supplies
•Traceability
•Process control
•Checking, inspecting, measuring and testing
•Non-conforming product or services
•Corrective action
•Protection of quality
•Training
•Statistical Process Control (SPC)
•Quality system audit
Software Quality CS2 12
Nathan Baddoo

13. Quality Management Systems (QMS)
for Software
Statistical Process Control (SPC)
•Process flow charting - used to show what is done
•Tally charts - to show how often something is done
•Histograms - to show overall variation
•Pareto analysis - to highlight the big problems
•Cause and effect diagrams - to indicate causes of
problems and errors
•Scatter diagrams - to highlight relationships
•Control charts - to show which variation to control
Software Quality CS2 13
Nathan Baddoo

14. Quality Management Systems (QMS)
for Software
Principal aspects of a QMS for Software
•Development procedures
•Quality control
•Quality improvement
•Quality assurance
Software Quality CS2 14
Nathan Baddoo

15. Quality Management Systems (QMS)
for Software
Conclusion
•Software quality approaches are rooted in manufacturing.
•Most are people oriented
•Emphasise on processes.
•Need for statistical process control.
•QA alone is insufficient. Quality improvement is important.
•Key components of QMS for software are: development
procedures, quality control, quality improvement and quality
assurance
Software Quality CS2 15
Nathan Baddoo