Constructing and testing software maintainability assessment models

Software metrics are used to quantitatively characterize the essential features of software. The paper investigates the use of metrics in assessing software maintainability by presenting and comparing seven software maintainability assessment models. Eight software systems were used for initial construction and calibrating the automated assessment models, and an additional six software systems were used for testing the results. A comparison was made between expert software engineers´ subjective assessment of the 14 individual software systems and the maintainability indices calculated by the seven models based on complexity metrics automatically derived from those systems. Initial tests show very high correlations between the automated assessment techniques and the subjective expert evaluations