A software system is a complex artefact involving several aspects, such as requirements and behavioural workflows. Information systems engineering has generated several approaches to create software models reflecting these aspects. To obtain the necessary integration, the relations between the involved models must be expressed formally. Currently, this necessity is particularly evident in systems built to assist users in performing knowledge generation, such as scientific knowledge-management systems. Model-Driven Engineering provides some interoperability techniques for expressing inter-model relations. In this paper, a specific metamodel is proposed for integrating different modelling perspectives of software systems built for assisting users in knowledge generation. Furthermore, the integration metamodel is initially validated through its application to the integration of modelling perspectives of a system to assist knowledge generation in the cultural heritage domain. The integration metamodel proposed allows the system to make knowledge generation decisions by manipulating the relations between the involved models on behalf of the user.