[all] Maintainability index for files and folders

[rupam925]

PMD analyzer should give the maintainability index for the files and folders. It should give metrics for how much the code is maintainable.

[adangel]

Thanks for your suggestion.
Can you elaborate a bit, what this maintainability index is and how this could be determined?

[rupam925]

Maintainability Index is a software metric which measures how maintainable (easy to support and change) the source code is. The maintainability index is calculated as a factored formula consisting of Lines Of Code, Cyclomatic Complexity and Halstead volume. It is used in several automated software metric tools, including the Microsoft Visual Studio 2010 development environment, which uses a shifted scale (0 to 100) derivative.
First we need to measure the following metrics from the source code:
V = Halstead Volume
G = Cyclomatic Complexity
LOC = count of source Lines Of Code (SLOC)
CM = percent of lines of Comment (optional)
From these measurements the MI can be calculated:
The original formula:
MI = 171 - 5.2 * ln(V) - 0.23 * (G) - 16.2 * ln(LOC)
The derivative used by SEI is calculated as follows:
MI = 171 - 5.2 * log2(V) - 0.23 * G - 16.2 * log2 (LOC) + 50 * sin (sqrt(2.4 * CM))

[linusjf]

Quality scores have also been discussed elsewhere. Linking in... #2942