The design of conventional process plants is guided by the idea of structuring the process in functional units. Because of cost reduction this design is often neglected during the implementation phase. There is a huge potential in the re-modularization looking at the re-usability which directly effects the engineering efficiency when developing new plants. Furthermore, there is the possibility to create modularized KPIs. Those can be aggregated to plant-wide KPIs to evaluate the overall plant performance and status. In this paper the authors are presenting a concept for the detection of virtual modules in existing plant topologies. The plant topology is therefore transformed into a searchable graph. With the help of extended search algorithms and the definition of functional patterns it is now possible to identify all possible virtual module within a plant topology. Through a prototypical implementation, visualizing the identified modules in the graph, a proof of concept is shown.