Presented at Agile in Business conference at Bangalore. This presentation focuses on code metrics that can be used as lead indicators to effectively control and predict the application quality

1. Agile with CMMi - A potent blend…
Mosesraj R
Collabera Solutions
Bangalore
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2. CMMI & Agile
Level 4/5
SCRUM/XP
Practices
Principles
Level 2/3 Manifesto
Organization Project level
focus focus
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3. Fundamental challenge - measurability
People
Engineering
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4. Genrich Altshuller scanned 400,000 patent
descriptions, and found that only 2% were really
new. This means, 98% of all new problems can
be solved using previous experience/learning(s).
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5. 5

6. “. . . .Yo u r
hands can’t
Structural
hit what
application profile
Code
structure
Test case
adequacy your eyes
can’t
s e e … . .”
Requirements
structure
Muhammad Ali
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7. Typical Lifecycle in Collabera
System
Requirem Architectu Design & Unit
/Functiona
ents re Coding Testing
l Testing
Requirements &
Continuous Integration & Iteration
Architecture Baseline
Releases
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8. 8

9. 9

10. Can ‘defect prone’ tendency be isolated?
• A study on eclipse (published in PROMISE 2007)
– Defects are mapped to less than 15% of files
• Study on Firefox
– Security issues are mapped a low % of code
(predominantly java script interpreter)
• Publication from CAST
– In a US based bank around 30% defects in tests
are attributed to identifiable poor code structures
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11. The problem of plenty…
Cyclomatic % comment Lines Density of comment Violations
complexity lines
%Branch Java NCSS Public undocumented Complexity
API distribution by
Statements
method
Depth of Npath Complexity Duplicated lines
Inheritance Duplicated blocks Complexity
Calls/method Class Fan Out distribution by class
Complexity Number of children
Methods / Class
Afferent couplings
Class Data Abstraction File dependencies to
Class Coupling
coupling Lack of cohesion cut
Maintainability methods
Index Boolean Expression
Package dependencies
complexity
to cut
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12. Influence ofSIT with engineering metrics
Correlating complexity attribute II
% Branches Block Depth
% Branches Block Depth
Cyclomatic Complexity
Max Cyclomatic Complexity
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Bridging the eagle’s eye and worm’s view Slide 12

13. Composite parameter analysis
Study from European university
Number of Class vs SIT defects
2% 1%
1%
4%
 Key parameters measured
 Cyclomatic complexity/LOC
 No. of methods/class
 No. of Calls/method
92%  LOC/method
8% of classes is contributing to 100% of SIT
defects
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14. Toxicity Analysis
Correlates to
AT & SIT
defects
Detailed study of the data shows most of the SIT & AT defects are occurring amongst the top four Java classes
shown in the sample data above which have highly toxic code with high method length
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15. UC complexity v/s cyclomatic complexity
2.3.47.2
2.3.41.2 2.3.42.2
2.3.43.2 2.3.44.2 2.3.13.2
2.3.15.2 2.3.48.2 2.3.11.2
2.3.23.2
2.3.20.2
2.3.1.2 2.3.19.2 2.3.20.2 2.3.30.2 2.3.32.2
2.3.37.2
2.3.16.2
2.3.25.2
2.3.49.2
2.3.38.2 2.3.33.2 2.3.36.2 2.3.4.2 2.3.5.2
2.3.26.2
2.3.2.2
2.3.50.2
2.3.17.2
2.3.39.2
2.3.34.2
2.3.52.2 2.3.6.2 2.3.9.2
2.3.27.2 2.3.7.2
2.3.45.2
2.3.18.2
2.3.40.2
2.3.35.2
2.3.12.2 2.3.10.2 2.3.53.2 2.3.10.1
2.3.22.2 2.3.46.2
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16. See code akin to a city map...
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17. Developer’s Structural Analysis Kit
Parameters Tools Process
• Max /Avg. Cyclomatic • Source monitor • Integration to build tools
Complexity • PMD • Prior to code review
• Methods Per Class • Checkstyle • Analysis before release
• Avg Statements Per Method • iPlasma & Code city
• % Branch statements • Sonar
• Max Block Depth
• Cyclomatic complexity
• No. of Calls/method
• LOC/method
• LOC/Program
• Fan out
• Data abstraction coupling
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18. Shifting to the better – Project level
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19. Shifting to the better – Org level
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16
14
12
10
Dec-10
8
Dec-11
6
4
2
0
Max Code Methods per Statement Branches % Max Block
Complexity Class per Method Depth
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20. Improved Pre-SIT Detection
Dec-09 Dec-11 Till Date
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21. Shift in defect distribution
Requirements & Code Review Unit Test System Test Post Release
Design review
Pre Post
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22. Customer Satisfaction
Overall Engagement Level View
Engagement Planning Engagement Execution Engagement Results People
Overall 2010
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23. Qualitative Benefits
• Objective measures; language of developer
• Improve ability to isolate and deal with the
defective ones
• Improved risk management and transparency
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24. Thank
you
Mosesraj R - (mosesrajr@collabera.com)
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