Based on the availability of sensors, data and connectivity in manufacturing systems, Digital Twins (DTs) are increasingly used, e.g. for improving processes through advanced prediction or monitoring capabilities. With the increasing dissemination of the DT concept, it is to be expected that in the future there will be several DTs in a manufacturing system, each of which will pursue a different purpose and process different data. As a consequence, these DTs bring individual benefits, but are mostly used within a limited manufacturing system area. In addition to the originally intended use of individual DTs, this results in the potential to use their respective results or output data for other purposes in the manufacturing system (additional benefits). Therefore, the question of administrating several DTs within the same manufacturing system arises. While not only preventing redundancies, this also enables the synergetic use of DT capabilities. In order to systematize this benefit, this paper describes a procedure with which DTs can be integrated into the structure of a manufacturing system. Subsequently, a method for the systematic achievement of the described additional benefits is elaborated. The resulting overall procedure is illustrated using an exemplary application scenario.