My presentation to the Seattle Scrum Users group on 29th May, 2008

1. An Introduction to Agile
Engineering Practices
Kane Mar
1

2. “The New New Product
Development Game”
- Takeuchi and Nonaka
2

3. photo: http://www.flickr.com/photos/nicmcphee/
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4. 4

5. From: Kent Beck
To: Jeff Sutherland <jsutherland>
Reply: 70761.1216@compuserve.com
Date: Mon, 15 May 1995 18:01:15 -0400 (EDT)
Subj: HBR paper
_________________________
Is there a good place to get reprints of the SCRUM paper from
HBR? I've written patterns for something very similar and I want to
make sure I steal as many ideas as possible.
Kent
5

6. Continuous Integration
6

7. What is Continuous
Integration?
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8. “Continuous Integration is a software
development practice where members of a
team integrate their work frequently,
usually each person integrates at least daily
- leading to multiple integrations per day.
Each integration is verified by an
automated build (including test) to detect
integration errors as quickly as possible.”
-Martin Fowler
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9. Commit
9

10. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
10

11. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
Checkout
11

12. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
Checkout
12

13. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
Checkout
13

14. 14

15. Why is Continuous Integration
important?
15

16. 1. Reducing Risk.
16

17. When we are integrating the
product all the time the risk of a
failed integration is spread
throughout the duration of the
project ...
17

18. rather than being left until the
end.
18

19. 2. Behavior.
19

20. If doing a complete build and
test of any product is difficult ...
20

21. doing it “continuously” is very
difficult.
21

22. Teams need to develop different
ways of working.
22

23. Never letting the build break.
23

24. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
A broken build or
Checkout integration test
here ...
24

25. 1. Compile & Build
Commit 2. Unit Tests
3. Integration Tests
4. Report Errors
A broken build or
Checkout integration test
here ...
will get propagated
here, here and here.
25

26. The Friday Afternoon Pattern of
broken builds.
26

27. Delivering smaller increments
of well tested functionality.
27

28. Investing in automated testing
frameworks.
28

29. Test, Test and Test again.
29

30. I believe that all teams should
practice CI.
30

31. The tools are free, like free beer.
31

32. The only price to pay for
introducing CI is ...
32

33. education.
33

34. References
http://www.martinfowler.com/articles/
✦
continuousIntegration.html
✦ http://cruisecontrol.sourceforge.net/
✦ http://www.jetbrains.com/teamcity/
✦ http://luntbuild.javaforge.com/
✦ https://hudson.dev.java.net/
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35. Test Driven Development
35

36. What is Test Driven
Development?
36

37. 1. Add a test
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38. 2. Run all test and see the new
ones fail
38

39. 3. Write some code
39

40. 4. Run the automated tests and
see them succeed
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41. 5. Refactor
41

42. Red/Green/Refactor
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43. Why is TDD important?
43

44. TDD is a method of designing
software, not merely an
approach to testing.
44

45. “We found that test-first
students on average wrote more
tests and, in turn, students who
wrote more tests tended to be
more productive.”
- Erdogmus, Hakan; Morisio,
Torchiano
45

46. Over a period of time, TDD will
lead to suite of automated
integration tests.
46

47. References
Erdogmus, Hakan; Morisio, Torchiano. “On the Effectiveness of Test-first
✦
Approach to Programming,” Proceedings of the IEEE Transactions on Software
Engineering, 31(1). January 2005. (NRC 47445). “We found that test-first students
on average wrote more tests and, in turn, students who wrote more tests tended to
be more productive.”
Newkirk, JW and Vorontsov, AA. “Test-Driven Development in Microsoft .NET,”
✦
Microsoft Press, 2004.
Feathers, M. “Working Effectively with Legacy Code,” Prentice Hall, 2004
✦
Beck, K. “Test-Driven Development by Example,” Addison Wesley, 2003
✦
Muller, Matthias M.; Padberg, Frank. “About the Return on Investment of Test-
✦
Driven Development (PDF)” Universitat Karlsruhe, Germany
47

48. Refactoring
48

49. What is Refactoring?
49

50. “Refactoring is a disciplined technique for
restructuring an existing body of code,
altering its internal structure without
changing its external behavior.”
- Martin Fowler
50

51. “Each transformation (called a 'refactoring')
does little, but a sequence of
transformations can produce a significant
restructuring.”
51

52. double disabilityAmount() {
if (_seniority < 2) return 0;
if (_monthsDisabled > 12) return 0;
if (_isPartTime) return 0;
// compute the disability amount
double disabilityAmount() {
if (isNotEligableForDisability()) return 0;
// compute the disability amount
52

53. “Refactoring is a disciplined technique for
restructuring an existing body of code,
altering its internal structure without
changing its external behavior.”
- Martin Fowler
53

54. How do we establish that the
behavior is unchanged?
54

55. Continuous Integration
and
Test Driven Development
55

56. The term Refactoring is poorly
used.
56

57. “If somebody talks about a
system being broken for a
couple of days while they are
refactoring ...”
57

58. “you can be pretty sure they are
not refactoring ... “
58

59. “Refactoring is a very specific
technique, founded on using
small behavior-preserving
transformations”
- Martin Fowler
59

60. References
Fowler, Martin (1999). “Refactoring.” Addison-Wesley. ISBN 0-201-48567-2.
✦
http://martinfowler.com/bliki/RefactoringMalapropism.html
✦
60

61. Pair Programming
61

62. What is Pair Programming?
62

63. Two team members working on
the same code base and working
side-by-side
63

64. photo: http://www.flickr.com/photos/improveit/
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65. “I told you Slashdot was more popular than Digg”
65

66. Modern software development is full of drama ...
66

67. photo: http://www.flickr.com/photos/improveit/
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68. photo: http://www.flickr.com/photos/improveit/
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69. The thrill of victory ...
69

70. And the agony of defeat.
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71. Why is Pair Programming
important?
71

72. Pair Programming significantly
reduces the number of defects,
and greatly increase the quality
of the code.
72

73. It is, however, very difficult to
introduce.
73

74. There are many issues mostly
related to loss of personal space
and lack of privacy.
74

75. Why do we care?
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76. 76

77. 80% of the cost of software is
incurred after it has gone live.
77

78. What would it mean to you if
your cost of change was linear
rather than exponential?
78

79. Thank You!
79