A machine learning model to classify the feature model maintainability

Software Product Lines (SPL) are generally specified using a Feature Model (FM), an artifact designed in the early stages of the SPL development life cycle. This artifact can quickly become too complex, which makes it challenging to maintain an SPL. Therefore, it is essential to evaluate the artifact's maintainability continuously. The literature brings some approaches that evaluate FM maintainability through the aggregation of maintainability measures. Machine Learning (ML) models can be used to create these approaches. They can aggregate the values of independent variables into a single target data, also called a dependent variable. Besides, when using white-box ML models, it is possible to interpret and explain the ML model results. This work proposes white-box ML models intending to classify the FM maintainability based on 15 measures. To build the models, we performed the following steps: (i) we compared two approaches to evaluate the FM maintainability through a human-based oracle of FM maintainability classifications; (ii) we used the best approach to pre-classify the ML training dataset; (iii) we generated three ML models and compared them against classification accuracy, precision, recall, F1 and AUC-ROC; and, (iv) we used the best model to create a mechanism capable of providing improvement indicators to domain engineers. The best model used the decision tree algorithm that obtained accuracy, precision, and recall of 0.81, F1-Score of 0.79, and AUC-ROC of 0.91. Using this model, we could reduce the number of measures needed to evaluate the FM maintainability from 15 to 9 measures.