A modified Yule process to model the evolution of some object-oriented system properties

We present a model based on the Yule process, able to explain the evolution of some properties of large object-oriented software systems. We study four system properties related to code production of four large object-oriented software systems – Eclipse, Netbeans, JDK and Ant. The properties analysed, namely the naming of variables and methods, the call to methods and the inheritance hierarchies, show a power-law distribution as reported in previous papers for different systems. We use the simulation approach to verify the goodness of our model, finding a very good correspondence between empirical data of subsequent software versions, and the prediction of the model presented.