Dn-based design quality comparison of industrial Java applications

The normalized distance from the main sequence, denoted D_n, is a popular object-oriented metric introduced by Martin in 1994. While the metric has been designed for assessment of individual packages it has also been applied in practice to quality assessment of entire software architectures. This gap between the industrial practice and theoretical understanding has been recently addressed for Java open-source systems. Based on study of a benchmarks collection the authors proposed a statistical model characterizing (a) the average value of D_n, and (b) distribution of D_n. Contribution of the current work is twofold. First, we show feasibility of application of the D_n-based assessment above to commercial Java applications. Second, we validate the approach by showing that the results obtained are consistent with those obtained by means of a series of independent studies, such as layering, presence of cyclic dependencies and Chidamber´s and Kemerer´s metrics.