This document discusses a study on whether distributed development affects software quality. The study examined Microsoft's development of Windows Vista, which involved 3,300+ binaries, 3,000 developers across 59 buildings and 3 continents. The results showed that there was no significant difference in the number of bugs between code developed by distributed teams versus collocated teams. Distributed development was not found to negatively impact software quality for the Windows Vista project.

1. Does Distributed Development
Affect Software Quality?
by
C. Bird, N. Nagappan, P. Devanbu,
H. Gall and B. Murphy
presenter:
Sebastian T. Hafner

2. developer locations
Saarbrücken
2

3. developer locations
Redmond Saarbrücken
Hyderabad
Brasilia
2

4. developer locations
Redmond Saarbrücken
Hyderabad
Brasilia
location diversity
➜ riskier and more challenging development?
2

5. Microsoft Vista
3300+ binaries
3000 developers
59 buildings
3 continents
3

6. level of distribution
Building
Cafeteria
Campus
Locality
Continent
World
4

7. Building
more face-to-face meetings
informal contact
synchronous communication
Building Cafeteria Campus Locality Continent World
5

8. Cafeteria
information exchange during lunch
impromptu meetings
Building Cafeteria Campus Locality Continent World
6

9. Campus
from building to building by foot
rapid meetings
Building Cafeteria Campus Locality Continent World
7

10. Locality
reachable by car within 1 day
same timezone
Building Cafeteria Campus Locality Continent World
8

11. Continent
rare face-to-face meetings
different timezones
cultural similarities
Building Cafeteria Campus Locality Continent World
9

12. World
rare face-to-face meetings
low synchronous communication
language differences
cultural differences
Building Cafeteria Campus Locality Continent World
10

13. Example
cmroute.dll
cmroute.cpp
cmroute.h
etc.
11

14. Example
Asia
Hyderabad
cmroute.dll building 1
cmroute.cpp
cmroute.h Joe ( 16)
etc. Bob ( 10 )
Sarah ( 8 )
Cindy ( 6 )
11

15. North America Example
Asia
Hyderabad
cmroute.dll building 1
cmroute.cpp
cmroute.h Joe ( 16)
etc. Bob ( 10 )
Sarah ( 8 )
Cindy ( 6 )
11

16. North America Example
Redmond
building 43 Asia
Tom ( 6 ) Hyderabad
cmroute.dll
building 21 building 1
Stephan ( 3 ) cmroute.cpp
cmroute.h Joe ( 16)
etc. Bob ( 10 )
Sarah ( 8 )
Cindy ( 6 )
11

17. North America Example
Redmond
building 43 Asia
Tom ( 6 ) Hyderabad
cmroute.dll
building 21 building 1
Stephan ( 3 ) cmroute.cpp
cmroute.h Joe ( 16)
etc. Bob ( 10 )
Charlotte Sarah ( 8 )
Cindy ( 6 )
building 2
Melanie ( 12 )
11

18. level of distribution
Building 68 %
Cafeteria 2.3 %
Campus 17 %
Locality 5.6 %
Continent 0.2 %
World 5.9 %
12

19. relative change
in bug density
overall normalized to developer count
20
15
10
5
0
-5
-10
Building Cafeteria Campus Locality Continent World
13

20. result
14

21. result
During the development of Windows Vista:
There weren’ t signi cant more bugs
in distributed code parts than in
collocated codeparts!
14

22. Discussion :)
Mining Software Archives
Seminar SS 2010