1. Software bugs
Svetlana Dubyk
01-09-2012

2. Agenda
Mistake metamorphism
First software bug
Bug fixing cost
Reasons why bugs get into software
Software bug classification
Types of software bugs
Software bug impact
Worst software bugs

3. Mistake metamorphism
▪ Mistake
▪ Anomaly
▪ Fault
▪ Failure
▪ Error
▪ Exception
▪ Crash
▪ Bug
▪ Defect
▪ Incident
▪ Side effect

4. First software bug

5. Bug fixing cost

6. Reasons why bugs get into
software
Last minute changes
Developed by humans
Communication failure
Poor developing techniques
Lack of trained testing staff
Buggy third-party instruments
Misapplication of technology
Unrealistic development timeframe

7. Software bug classification
Priority/ Urgency
Severity/ Impact
Related module/ component
Probability/ Visibility
Related dimension of quality
Phase detected
Phase injected

8. Types of software bugs

9. Consequences of bugs in
software

10. Mariner I space probe
"The most
expensive
hyphen in
history"
Dates: 1962
Cause: error in
formula
Consequences:
rocket diverted from its
intended path on launch
-> was destroyed
Over 18.2 million dollars
were lost.

11. Soviet gas pipeline
Dates: 1982
Cause: "race condition"
Consequences: at least 5 patients died, many
more were injured
"The largest
non-nuclear
explosion in
the planet's
history"

12. Therac-25 medical
accelerator
Dates: 1985-1987
Cause: "race
condition"
Consequences:
at least 5 patients
died, others were
seriously injured

13. Useful links
http://www.testingexperience.com/testingexperience17_03_12.pdf
http://softwaretestingfundamentals.com/defect/
http://en.wikipedia.org/wiki/Software_bug
http://en.wikipedia.org/wiki/List_of_software_bugs
http://software-testing-zone.blogspot.com/2008/12/why-are-bugsdefects-in-software.html
http://www.articlesbase.com/programming-articles/software-bug-and-their-common-types-895408.html
http://news.cnet.com/8301-1023_3-57464559-93/leap-second-bug-causes-site-software-crashes/
http://gizmodo.com/5467388/software-bug-causes-toyota-recall-of-almost-half-a-million-new-hybrid-cars
http://top-10-list.org/2010/05/03/ten-costliest-software-bugs/
http://www.softwaretestingstuff.com/2008/05/classification-of-defects-bugs.html
http://www.softwaretestingconcepts.com/bug-classification-based-on-severity-and-priority
http://www.cbsnews.com/2100-205_162-551492.html
http://www.cse.lehigh.edu/~gtan/bug/softwarebug.html
http://royal.pingdom.com/2009/03/19/10-historical-software-bugs-with-extreme-consequences/
http://my.safaribooksonline.com/book/software-engineering-and-development/software-testing/0672327988/software-testingbackground/ch01lev1sec4
http://www.v3.co.uk/v3-uk/news/1973196/software-bugs-cost-billions

14. Contact information
svetlana_dubyk
sveta.dubyk@gmail.com
sdu@ciklum.com
2012

15. Thank you!