1. A computer-implemented method comprising: receiving a plurality of concept instances comprising a first concept instance extracted from a first software system artifact of a software system and a second concept instance extracted from a second software system artifact of the software system, wherein the first software system artifact and the second software system artifact are associated with a first formal language and a second formal language respectively, and the first concept instance and the second concept instance are specific instantiations of at least one identified concept associated with the software system; identifying one or more relationships comprising a cross-artifact relationship between the first concept instance and the second concept instance or a relationship between at least one of the first concept instance or the second concept instance and at least one identified concept associated with the software system; and storing at least one of the one or more relationships comprising the cross-artifact relationship between the first concept instance and the second concept instance in one or more repositories, wherein the cross-artifact relationship specifies a relationship type that relates the identified concept to the first concept instance and the second concept instance.