MAINTAINABILITY INDEX


  • Maintainability Index - a measure of success

  • - Set of polynomial metrics developed at the University of Idaho
    - Uses Halstead’s effort/module and McCabe’s cyclomatic complexity/module, plus other factors
    - Validated in the field by Hewlett-Packard
    - Language independent
    - Index is a number between 0 and 100
    - Used primarily to determine if modules have a high, medium, or low degree of difficulty to maintain

  • HP concluded “modules with a MI less than 65 are considered difficult to maintain”


Previous slide Contents Next slide


From the Script: SLIDE 54 - Maintainability Index

The Air Force decided to use a Maintainability Index (MI) as a measure of their success in this reengineering effort.

This gathering of metrics and determination of metrics such as MI are a major part of K. Welker's thesis work. It is important to note that the metrics information in the monograph and papers have been reviewed by both his thesis advisory committee and by the OOPSLA program committee.

The MI used is a set of polynomial metrics developed at the University of Idaho, using Halstead's module and McCabe's cyclomatic complexity, plus some other factors.

The MI is used primarily to determine if code has a high, medium or low degree of difficulty to maintain. It ranges from 0..100 with larger numbers being better.

It is language independent and was validated in the field by Hewlett-Packard (HP). HP concluded that modules with a MI less than 65 are difficult to maintain.