The document discusses software quality assurance (SQA) and outlines various SQA activities including quality control, quality assurance, reviews, inspections, testing, measurement, and reporting. It describes the role of an SQA group in preparing SQA plans, auditing work products, and ensuring compliance. The document also discusses why SQA pays off by reducing defects, and outlines different review types and how to conduct effective reviews.

1. 1
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Chapter 8
Software Quality Assurance

2. 2
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Quality Concepts
general objective: reduce the “variation
between samples” ... but how does this apply
to software?
quality control: a series of inspections,
reviews, tests
quality assurance: analysis, auditing and
reporting activities
cost of quality
appraisal costs
failure costs
external failure costs

3. 3
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Why SQA Activities Pay Off?
cost to find
and fix a defect
100
10
log
scale
1
Req.
Design
code
testsystem
test
field
use
0.751.00
1.50
3.00
10.00
60.00-100.00

4. 4
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Software Quality Assurance
Formal
Technical
Reviews
SQA
Test
Planning
& Review
Measurement
Analysis
&
Reporting
Process
Definition &
Standards

5. 5
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Role of SQA Group
 Prepare SQA project plan
 Assist with developing project sw process description
 Review sw eng. activities to verify compliance
w/defined sw process
 Audit designated sw work products
 Ensure that deviations in sw and work products are
documented/handled IAW docum. Process
 Record any non-compliance and report it to senior
mgmt

6. 6
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Reviews & Inspections
... there is no particular reason
why your friend and colleague
cannot also be your sternest critic.
Jerry Weinberg

7. 7
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
What Are Reviews?
a meeting conducted by technical people for
technical people
a technical assessment of a work product
created during the software engineering
process
a software quality assurance mechanism
a training ground

8. 8
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
What Reviews Are Not!
They are not:
a project budget summary
a scheduling assessment
an overall progress report
a mechanism for reprisal or political
intrigue!!

9. 9
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
The Players
review
leader
producer
recorder reviewer
standards bearer (SQA)
maintenance
oracle
user rep

10. 10
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Conducting the Review
be prepared—evaluate
product before the review
review the product, not
the producer
keep your tone mild, ask
questions instead of
making accusations
stick to the review agenda
raise issues, don't resolve them
avoid discussions of style—stick to technical
correctness
schedule reviews as project tasks
record and report all review results
1.
2.
3.
4.
5.
6.
7.
8.

11. 11
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Review Options Matrix
trained leader
agenda established
reviewers prepare in advance
producer presents product
“reader” presents product
recorder takes notes
checklists used to find errors
errors categorized as found
issues list created
team must sign-off on result
IPR—informal peer review WT—Walkthrough
IN—Inspection RRR—round robin review
IPR WT IN RRR
no
maybe
maybe
maybe
no
maybe
no
no
no
no
yes
yes
yes
yes
no
yes
no
no
yes
yes
yes
yes
yes
no
yes
yes
yes
yes
yes
yes
yes
yes
yes
no
no
yes
no
no
yes
maybe
*
*

12. 12
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Metrics Derived from Reviews
inspection time per page of documentation
inspection time per KLOC or FP
errors uncovered per reviewer hour
errors uncovered per preparation hour
errors uncovered per SE task (e.g., design)
number of minor errors (e.g., typos)
number of errors found during preparation
number of major errors
(e.g., nonconformance to req.)
inspection effort per KLOC or FP

13. 13
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Statistical SQA
Product
& Process
measurement
... an understanding of how
to improve quality ...
• collect information on all
defects
• find the causes of the
defects
• move to provide fixes for
the process

14. 14
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
Misc. Topics
Reliability
“the probability of failure-free program in a specified
environment for a specified time” [Musa]
Availability
SW Safety [Leveson]
ID hazards, categorize by criticality, risk
Analyze to assign severity and probability
Specify safety-related requirements

15. 15
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
More Misc. Topics
Poka-yoke devices
ISO-9000
Telecom equip., medical devices
Suppliers
Optional on own
ISO-9001
SQA Plan