agile code quality metrics
DESCRIPTION
A few KPIs for static code analysis for agile teamsTRANSCRIPT
Agile Code Quality Metrics
Gil Nahmias, CSP
Summary for Experts
Metrics–WTF/Minute– Abstractness vs.
Instability– Cyclomatic complexity– Test cases/Class– Defect Density– Fan in, Fan out– Code coverage, Test
coverage
Tools- ‘Metrics’
eclipse plugin- Ndepend- SourceMonitor- Klocwork
“Metrics are a carving knife when what you really need is a scalpel. Metrics can tell you something is wrong, but they can't give you much guidance about the precise cause.
disclaimer
In the case of clean code, the cause is discipline and professionalism”...”Fixing that problem is a matter of instilling pride of workmanship into the team”
-- Uncle Bob
Note before we start
What are we trying to understand
What we actually measure How does it
make people behave
Note before we start
What are we trying to understand
What we actually measure How does it
make people behave
Software Quality
# of bugs
Not record bugsHidden bugs, long stabilization, poor quality
Note before we start
What are we trying to understand
What we actually measure How does it
make people behave
Software Quality
Escaping Defects
Hidden bugs, long stabilization, poor quality
WTF/Minute – in code review
osnews.com/
comics
Abstractness vs. instability
blog.troytuttle.co
m
Software quality
Defect Density: number of defects per lines of code
Unit test density: number of unit test cases per feature or class.
+ve (actual = expected) -ve (actual != expected) stress
integration
MINIMUM
4
completeness
Code coverage: percentage of automatically tested code
Test coverage: percentage of automatically tested business scenarios
Code
Tests
Business
complexity
Fan-in: per type is the number of types that depends directly on it. [a.k.a. Afferent Coupling]
Fan-out: per type is the number of types it directly depends on. [a.k.a. Efferent Coupling]
Cyclomatic complexity: number of decisions that can be taken in a procedure [can be measured per class/feature]
