In this work we present the basic concepts for a dynamic plug-in-based software architecture using concepts from the Petri net-based MAS framework Mulan. By transferring the concepts of agent-orientation to a plug-in-based architecture we are able to design our application and the plug-inbased system on an abstract level. Moreover, general problems that evolve from a highly dynamic and configurable architecture have been solved by basing the conceptual design on multi-agent principles. The introduced concepts have been applied to the software architecture of the tool Renew. Categories and Subject Descriptors D.2.11 [Software Engineering]: Software Architectures; D.2.2 [Software Engineering]: Design Tools and Techniques—Petri nets General Terms Design Keywords Components, dynamic software architectures, high-level Petri nets, modeling, Mulan, multi-agent systems, nets-withinnets, plug-in architectures, reference nets, Renew