A configuration software (configurator) associates a knowledge base (KB) with a knowledge processing unit (PU). The KB describes all possible combinations of components while the PU overlays this knowledge with the customer requirements. Our work deals with the KB and the approaches, models, or tools for modeling configuration knowledge. Our goal is to present a small quantitative literature survey highlighting two work streams: the first one gathers modeling works dealing with constraint-based approaches while the second deals with ontologies, description logic, or object-oriented modeling approach. We will also consider hybrid approaches. We will present a quantitative analysis of published materials in Web of science over the last twenty years. The keywords occurrence versus time will also be studied in detail to identify tendencies in configuration knowledge modeling.