Towards automatic extraction of UML class diagrams: Creation of an annotated dataset for training deep models

Abstract

Software modeling relies heavily on UML class diagrams, essential tools for structuring a system’s entities, behaviors, and relationships. Yet, manually developing them from textual specifications remains a time-consuming task and subject to interpretation. This study proposes the creation of a corpus annotated according to a customized IOB schema, intended to train Named Entity Recognition (NER) models for the automatic extraction of UML elements from text. The schema integrates specific labels to accurately capture classes, attributes, methods, and relationships (association, aggregation, composition, inheritance), including their compound forms. The current corpus, built from 132 documents from various sources, includes more than 900 sentences and 11,000 manually annotated tokens. Particular attention was paid to the syntactic and semantic diversity of the texts, as well as to the linguistic quality, to ensure good generalization of the models. The empirical evaluation conducted with six Transformers models (BERT, RoBERTa, SpanBERT, XLNet, MiniLM and Electra) shows promising results, especially for classes and their relationships. This work thus lays the foundation for a reliable automation of UML class diagram generation from textual specifications, with strong potential for integration into software engineering environments and MDA processes.