Naresh and Bhavin's Presentation from the Pair Programming Workshop at Agile Chennai

1. Pair Programming
You will never work alone again!
Naresh Jain
naresh@agilefaqs.com
Licensed Under Creative Commons by Naresh Jain
1

2. What is Pair Programming ?
2

3. Video of a Sniper team working together
3

4. What did we see ?
Two guys working on the same task
Both have the same target
Both have different expertise
One executes the task
The other watches for external factors, evaluates the situation,
corrects him and validates success after execution
Two guys working as a team
Licensed Under Creative Commons by Naresh Jain
4

5. What is Pair Programming ?
5

6. src: ThoughtWorks India
6

7. src: ThoughtWorks India
6

8. Pairing
Station
src: ThoughtWorks India
6

9. Driver
Pairing
Station
src: ThoughtWorks India
6

10. Driver
Navigator
Pairing
Station
src: ThoughtWorks India
6

11. Next
line
of
code,
syntax,
API,
class
under
dev
Driver
Navigator
Pairing
Station
src: ThoughtWorks India
6

12. are
we
in
the
right
direction?,
Next
line
of
code,
requirements,
alternatives,
syntax,
API,
next
test
case,
class
under
dev
impact
Driver
Navigator
Pairing
Station
src: ThoughtWorks India
6

13. Isn't it a waste ?
Two developers will do the work of one
Junior guys will slow down seniors
Less work will get done
My cost will double
Why would I put two people on a job that just one can do?
Licensed Under Creative Commons by Naresh Jain
7

14. TICO TICO (Guitar Four-Hand Exchanging) Video
http://www.youtube.com/watch?v=CcsSPzr7ays
8

15. 9

16. 10

17. 11

18. 12

19. How does it Help?
Licensed Under Creative Commons by Naresh Jain
13

20. Continuous Review
14

21. Less Defects
Defects caught early
15

22. Improvement in the
Quality of the Design
16

23. Better Problem Solving
17

24. More Economical
18

25. “Pair-Pressure”
ensures timely delivery
19

26. Rapid Hands-on
Approach to Learning
20

27. Better Induction of
new Team Members
21

28. Better Induction of
new Team Members
22

29. Saved Effort on Intra-
Team Documentation
23

30. Less Distraction leading
to Higher Productivity
24

31. Improved Satisfaction
25

32. Sustainable Pace:
Helps you slow down
and think
26

33. Better Team Building
and Communication
27

34. Project Management:
Risk Mitigation Strategy
28

35. We are in the business of building software and this process
requires craft and skill, rather than a series of manual steps.
Programming requires lot of thinking, creating abstractions,
figuring out the logic and trying out things.
An evolutionary, iterative and collaborative process.
Its a lot more than just typing code.
(Using the keyboard or even worse, using the mouse)
29

36. A Normal Pair Programming Video
http://www.youtube.com/watch?v=q-QWdFa4awI
30

37. Consider the following...
An experiment on Pair Programming
at University of Utah
Licensed Under Creative Commons by Naresh Jain
31

38. Cost and savings
Licensed Under Creative Commons by Naresh Jain
32

39. Cost and savings
Licensed Under Creative Commons by Naresh Jain
33

40. Cost of fixing defects
Cost
of
defect
Time
Licensed Under Creative Commons by Naresh Jain
34

41. Cost of fixing defects
Cost
of
defect
Time
“IBM reported spending about $250 million repairing and reinstalling
fixes to 30,000 customer-reported problems.
That is over $8,000 for each defect!”
- “A Discipline for Software Engineering”, 1995, Humphrey, W.S.
Licensed Under Creative Commons by Naresh Jain
34

42. Incorporating pair-programming into a
software development process will help
yield software products of better
quality in less time with happier,
more confident programmers!
35

43. Points of resistance
Things to watch out for...
Licensed Under Creative Commons by Naresh Jain
36

44. Difficulty in convincing
stakeholders to let two
people work on one task
37

45. Everyone settles down
into a “Comfort Zone”
Pairing would disrupt it
38

46. Strong Code Ownership
39

47. People Who Don’t Care
40

48. Developers not involved
in Estimation and Planning
41

49. Inconsistent
Workstation Setup
42

50. Small Work Area
(Cubicles)
43

51. Techniques of Pairing
Licensed Under Creative Commons by Naresh Jain
44

52. Ping-Pong Pairing
45

53. Keyboard n Mice Pairing
46

54. Selective Pairing
47

55. Cross functional Pairing
48

56. Distributed Pairing
49

57. Tips n Tricks
Licensed Under Creative Commons by Naresh Jain
50

58. Pairing Stations
51

59. Pair Rotation with
Pair Hinging
52

60. Promiscuous
Pair Programming
53

61. Pairing Round
54

62. Pair Stairs
55

63. Spikes
56

64. Pairing Smells
Things to Watch out for...
Licensed Under Creative Commons by Naresh Jain
57

65. Pair Programming Anti Patterns Video
http://www.youtube.com/watch?v=ReuFZYtGeCc
58

66. No Pair Rotation
59

67. Only one person driving
Distracted Pair
60

68. Selective Pairing closer
to a Release
61

69. Manager decides the Pairs
62

70. When its not necessary?
Tasks which involve Mundane Work (may be)
Trivial bug fixes like Typos
One person in the Pair is Sick
Licensed Under Creative Commons by Naresh Jain
63

71. F.A.Q.s
How do you do estimation? Its 2 people working on one task now.
How do you do performance reviews for individuals?
Can we keep it optional for some people on a team?
Licensed Under Creative Commons by Naresh Jain
64

72. References
The Costs and Benefits of Pair Programming
- Laurie Williams & Alistair Cockburn
Strengthening the Case for Pair-Programming
- Laurie Williams, Robert R. Kessler, Ward Cunningham & Ron Jeffries
On the Economic Feasibility of Pair Programming
- Hakan Erdogmus & Laurie Williams
Licensed Under Creative Commons by Naresh Jain
65

73. Thank You!
Questions?
Licensed Under Creative Commons by Naresh Jain
66