This document discusses software quality management and assurance. It defines quality as conformance to requirements, standards, and implicit expectations. It emphasizes that quality management involves activities throughout the software development process, including planning, reviews, testing, documentation control, and compliance. The software quality assurance group is responsible for quality assurance planning, oversight, record keeping, analysis and reporting to ensure standards and processes are followed.

1. Software Project Management
Lecture # 10

2. Outline
 Quality Management (chapter 26)
 What is quality?
 Meaning of Quality in Various Context
 Some quality concepts
 SQA
 SQA activities

3. Quality Management
 Quality Management (often called Software Quality
Assurance) is an umbrella activity that is applied
through out the software process.
 Every one involved in software engineering process is
responsible for quality.
 Emphasis on quality in all software engg. activities
reduces the amount of rework that the software engg.
team must do
 this eventually lowers costs, improves time to market
 The team must identify SQA activities that will filter
errors out of the work products before they are
passed on. But before doing so,
 they must define software quality at different levels of
abstraction
 SQA Plan is created to define the quality strategy of the team

4. Quality Management
 It encompasses
 Software quality assurance process
 Specific quality assurance & quality control
tasks (including FTRs and testing strategies)
 Effective SE practice (methods & tools)
 Control of all software work products & changes
made to them
 A procedure to ensure compliance with software
dev. Standards
 Measurement & reporting mechanism

5. What is Quality?
 British Standard Institute’s definition
 Quality is totality of features & characteristics of
a product or service which relate on its ability to
satisfy a given need
 American Heritage Dictionary definition
 Quality is characteristic or attribute of something
 Quality of Software
 Quality of Software is software that does what it
is supposed to do
 customer dissatisfaction is lack of quality

6. Meaning of Quality in Various Context
 In Manufacturing
 Quality means that the developed product
should meet its specification
 In Software Development
 Quality would mean that a software product
conforms to its specification
 Software specification should be oriented towards
customer requirements.
 There may be some implicit requirements like
maintainability, usability, etc. but they are not included
in the specification

7. Meaning of Quality in Various Context
 Practically , its very difficult to write complete
software specifications/ characteristics
 Therefore, although the product conforms to
its specifications, it may not satisfy the
customer as hence may not be considered as
a high quality product

8. Another school of thought …
 Quality can be achieved by defining
standards & organizational quality
procedures that check that these standards
are followed by the software development
team
 Besides standards & procedures there are
intangible aspects also involved in software
quality like elegance, readability, etc.

9. Quality Concepts
 Quality of design
 Refers to the characteristics that designers specify for an
item
 Focuses on requirements, specifications & design of
system
 Quality of conformance
 Is the degree to which the design specifications are
followed during manufacturing
 Focuses primarily on implementation
 User satisfaction
 Robert Glass suggested the following relationship:
 Compliant product + good quality + delivery within
budget & schedule

10. Quality Concepts
 Quality Control
 Definition & enhancement of processes that ensure
the software development team has followed project
quality procedures & standards
 Quality Control is a series of inspections, reviews &
tests used through out the development cycle to
ensure that each work product meets the
requirements placed on it
 It includes feed-back loop to the process that created
the work product
 The combination of measurement & feedback helps
to fine tune the process when work products fail to
meet their specification

11. Quality Concepts
 Quality Assurance
 The process of defining how software quality can
be achieved & how the development organization
knows that the software has the required level of
quality
 It involves establishment of a framework of
organizational procedures & standards that lead
to high quality software
 It consists of a set of auditing & reporting
functions that assess the effectiveness of quality
control activities.
 The aim is to provide management with facts &
figures and proofs that product quality is meeting
its goals

12. Quality Concepts
 Variation Control
 Variation control is the heart of quality control
 Variation control may be equated to quality
control
 Manufacturers aim to minimize the variation
among the products that are produced
 For software projects, from one project to
another, we may want to minimize the difference
between predicted resources needed to
complete project and actual resources used,
including staff, equipment, and calendar time

13. Quality Concepts
 Cost of Quality
 It includes all costs incurred in performing quality
related activities
 Cost of quality studies are conducted to
 Provide a baseline for current cost of quality
 Identify opportunities for reducing cost of quality
 Provide normalized basis of comparison (usually in
dollars)
 Quality costs are divided into
 Prevention costs
 Appraisal costs
 Failure costs

14. Quality Concepts
 Quality costs
 Prevention costs relate to
 Quality planning
 Formal technical reviews
 Test equipment
 training
 Appraisal costs relate to
 Activities to gain insight into product – “first time
through” each process, e.g.,
 In-process and inter process inspection
 Equipment calibration &maintenance
 testing

15. Quality Concepts
 Quality costs
 Failure costs
 Those that would disappear if no defects appeared
before shipping a product to customer
 Failure costs subdivided into 2 types
 Internal failure costs (related to defects found before
product is shipped)
 Rework, repair & failure analysis mode
 External failure costs (related to defects found after
product is shipped)
 Complaint resolution, product return and
replacement, helpline support & warranty work

16. Relative cost of correcting an
error
 Refer to figure 26.1
0
20
40
60
80
100
120
140
160
180
200
Req. Design Code Dev.
Test
System
test
Field Op

17. Software Quality Assurance
Although there are many definitions of quality but for
our purposes, software quality is:
 Conformance to …
 the explicitly stated functional & performance requirements,
 explicitly documented development standards &
 implicit characteristics that are expected of all professionally
developed software
 This definition emphasizes on 3 important points
 S/W requirements – a foundation from which quality is
measured
 Standards – define development criteria against which S/W is
engineered
 Implicit requirements – often go unmentioned but if not met,
can cause suspicion in quality

18. Who does it?
 Prior to 20th
Century
 SQA was responsibility of the craftsperson
 During 1950s and 1960s
 Responsibility of programmer
 Today responsible ones are …
 S/W Engrs. (Apply technical methods & measures, Conduct
FTRs & perform planned testing)
 Project managers
 Customers
 Sales Person
 SQA group (Serves as customer’s in-house representative,
Looks at S/W from customer’s point of view, Assists the S/W
Engrs team to achieve quality)

19. SQA
 SQA is an activity that is applied throughout the
software process and not after the software has
been developed
 SQA covers the following
 Quality management approach
 Effective s/w engineering technology (methods & tools)
 Formal technical reviews (applied throughout the process)
 A multi-tiered testing strategy
 Control of software documentation & changes made to it
 A procedure to assure compliance with software
development standards
 Measurement & reporting mechanism

20. SQA Group & SQA Activities
 SQA group is responsible for QA planning, oversight,
record keeping, analysis and reporting
 SEI recommends the following set of SQA group
activities:
 Prepares an SQA plan for project
 Participates in the development of project’s software
process description
 Reviews s/w engg activities to verify compliance with
defines s/w process
 Audits designated s/w work products to verify compliance
 Ensures that deviations in s/w work & work products are
documented
 Records any non compliance & reports to senior
management
 SQA groups also participates in change management
& help to collect & analyze s/w metrics