3. Code Metrics
What are they?
Why should I care?
Lines of Code (LOC)
Cyclomatic Complexity
Class Coupling / Coupling Between Objects (CBO)
Depth of Inheritance Tree (DIT)
Maintainability Index
Using the Tool Window

4. What are they?
“[…]a measure of some property of a piece of software
or its specifications […]”
http://en.wikipedia.org/wiki/Software_metric
“[…] a set of software measures […]”
http://msdn.microsoft.com/en-us/library/bb385914.aspx

5. Why should I care?
Find those areas that are (statistically) more likely to
produce problems
Determine where to focus limited resources
Understand the current state of a solution / project
Keep track of where we have been and where we are
going

6. Lines of Code (LOC)
Basic Info
Raw count of IL lines
Not a good measure by itself
Stats
N/A when used alone
Code Analysis
N/A
http://academic.research.microsoft.com/Paper/2101790.aspx

7. Cyclomatic Complexity
Basic Info
Count of decisions
More decisions means
more errors
Used often with LOC
Stats
10
Suggested upper limit
Code Analysis
CA1502
Avoid excessive complexity
25
http://www.mccabe.com/pdf/mccabe-nist235r.pdf

8. Depth of Inheritance (DIT)
Basic Info
The maximum length from the node to the root of the inheritance tree
Three assumptions
Deeper == harder to predict behavior
Deeper == greater design complexity
Deeper == more reuse of code
Stats
Low
Less complex
Less reuse of code
High
More complex
More reuse of code
5 or 6 for upper limit
Code Analysis
CA1501
Avoid excessive inheritance
http://www.pitt.edu/~ckemerer/CK%20research%20papers/MetricFor
4 OOD_ChidamberKemerer94.pdf

9. Class Coupling /
Coupling Between Objects (CBO)
Basic Info
Number of classes a
single class uses
Stats
9
Upper limit
Code Analysis
CA1506
Avoid excessive class coupling
80 for class
30 for method http://www.pitt.edu/~ckemerer/CK%20research%20papers/MetricForOOD_Chidamber
Kemerer94.pdf

10. Maintainability Index
Basic Info
Calculates an index value between 0 and 100 that represents the relative
ease of maintaining the code
Stats
High == good
Low == bad
Ratings
Green (20 – 100)
Yellow (10 – 19)
Red (0 – 9)
Code Analysis
CA1505
Avoid unmaintainable code
19 or lower

11. Using the Tool Window