Halstead Maintainability Index

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Halstead Maintainability Index is one of the source-code metrics Understand computes across 17+ languages — browse them in the GUI, export and track them, or script them with the Python API.

Metrics overview

Halstead Maintainability Index

API ID: HalsteadMaintainIdx
Languages: Any
Targets: Files, Functions

Original Halstead Maintainability Index

This metric measures how easy it is to maintain and change code. It is calculated using the Halstead Volume , Strict Cyclomatic Complexity, Lines of Code (SLOC) and Comment to Code Ratio. (Coleman, Don, Dan Ash, Bruce Lowther, and Paul Oman. "Using Metrics to Evaluate Software System Maintainability." IEEE Computer, vol. 27, no. 8, 1994, pp. 44-49.)

The higher the metric the easier the code is to maintain.

Maintainability Index = 171
                        - 5.2 * ln(HalsteadVol)
                        - 0.23 * CyclomaticStrict
                        - 16.2 * ln(CountLineCode)
                        + 50 * sqrt(2.46 * RatioCommentToCode)

Treemap with red functions being the hardest to maintain