Software quality improvement expert Jan Princen and XBOSoft CEO Philip Lew discuss the use of Predictive Analytics to prevent software defects in this XBOSoft webinar on Defect Prevention.

1. XBOSoft, Inc. All Rights Reserved. 1
How to Reduce Costs and
Improve Quality with
Defect Prevention
with Jan Princen
#DefectPrevention

2. Defect Prevention
Applying Predictive Analytics To
Prevent Software Defects

3. XBOSoft
Dedicated to software quality improvement
Founded in 2006
We speed products to market with our expert:
• Software QA consulting
• Software testing
Global team with offices in San Francisco,Beijing
and Amsterdam
“Thorough, accurate and fast”
XBOSoft, Inc. All Rights Reserved. 3

4. House Rules
 Participants other than the speakers are muted
 Questions via the GoToWebinar control on the
right side of your screen or through Twitter
@XBOSoft
 Questions may be asked throughout the webinar -
we’ll try to answer them at the end
 You will receive info on recording after the webinar
XBOSoft, Inc. All Rights Reserved. 4
Webinar Hashtag: #DefectPrevention

5. Meet Our Speakers
Philip Lew
CEO and Founder, XBOSoft
• Relevant specialties and
passions
o Software quality process,
evaluation, measurement
and improvement
o Software quality in use /
UX design
o Mobile User Experience
and usability
o Cycling and travel
XBOSoft, Inc. All Rights Reserved. 5
Karla Smith
Marketing Manager, XBOSoft
• Emails you about our
industry hot topic
webinars
• Invites you to download
our latest trends in
software testing
whitepapers
XBOSoft Team

6. Guest Presenter
Jan Princen
XBOSoft, Inc. All Rights Reserved. 6
• Founder of Grip QA, which provides
software development intelligence
• Previously held executive positions at ISVs
and consulting firms in the US and Europe
• Is an acknowledged speaker and writer on
software quality improvement
• Holds a Masters degree from the University of Maastricht
• Father of two
• Enjoys Reading & Hiking
Contact: @princenjan @gripqa or jan@grip.qa

7. Would you wear these?

8. What is a defect?
Wikipedia - A software bug is an error, flaw,
failure, or fault in a computer program or
system that causes it to produce an incorrect or
unexpected result, or to behave in unintended
ways.
For whom?

9. No Defects? No Defects?

10. Many Defects
• Feature or a bug?
• Defects with different priority p1, p2 etc.
• Defects found before or after release
• Defects found by dev or by test
• Defects found internal or by users
• Quality types – usability, localization,
security etc.
• Etc.

11. A defect definition is more important
than using “the” definition
(for this purpose)
Get organization / team /unit / stakeholder agreement on
what the defect is that you want to prevent
Hard part often is getting business involved

12. Preventing Defects – How we got started?

13. Defects - Root Causes & Solutions
• Skill Gap Team Members  Find Risk Team
Members  Pair Up, Review Sessions
• Isolated Knowledge Areas  Find Risk
Modules  Different Task Division,
Cooperation between individuals and
Locations
• Different Expectations  Set KPIs  Track
Across Multiple Releases

14. Metrics That Matter
DRE – Defect Removal Efficiency
Total nr of defects found and fixed before
release / Total nr of defects found after X days
release
The Economics of Software Quality – Capers Jones

15. Metrics That Matter
Entropy – Measures the Rate of Change in a Software
Project - Amount of data required to count the number of
files changed with each commit recorded in source control
http://www.methodsandtools.com/archive/softwareentropy.php
Entropy
30dAvg
Issues
Created30d
Avg
Docker

16. Prevention starts with detecting patterns that cause
defects in the first place.
In a Software Project:
• Every file was written by one or more people
• Every bug fix touches on or more files
Applying Predictive Analytics To Defect Prevention:
We calculate the chance that ‘my’ files require a bug fix
Preventing Defects
Defect Correlation Analysis

17. In Depth (2)
• Authors have one or more commits with a total
number of lines changed
• Bug fixes have one or more commits with a total
number of lines changed
• Cross-reference file authors with bug fixes
Preventing Defects
Defect Correlation Analysis

18. File A was written for 75%
by person 2, but only
contained 25% of the bug
fix. So blue’s defect
contribution in File A is
75% * 25% = 18.75%. Add
up all files to get the total
contribution for each
author.
2 files that are both authored by two
developers, a defect is encountered and a bug
fix is implemented touching both of these files

19. Use the analysis to help
individual team
members and monitor
improvements
Understand whose
code bugs originate
from
Pick your required granularity – e.g. person, technology, module. We will
soon release these analysis for on the commit level.

20. Predictions on
the amount of
defects in
product based
on your
development
processUnderstand what
elements of your
development
could lower
defects in
production
Other Applications of Grip – KPI Predictions
Augment Human Decision Making
Thinking Fast and Slow - Kahneman

21. How to set this up:
1. Define what types of defects you want
to prevent
2. Log issue numbers with commits
3. Set up KPIs with stakeholders (DRE,
frequency of P1, …)
4. Connect with our data model and
dashboard (or create your own)
Jan@grip.qa

22. Post your webinar questions on Twitter @XBOSoft
You will receive an email with information on today’s webinar slides and
recording.
Join us to keep updated on all our webinars, reports and white papers:
facebook.com/xbosoft
+xbosoft
linkedin.com/company/xbosoft
Check out our blog: http://xbosoft.com/software-quality-blog/
Download our free white papers: http://xbosoft.com/knowledge-center/
Contact us with questions regarding our services or ideas for future webinars!
services@xbosoft.com
Thank you!
Q+A
www.xbosoft.com