An enormously rich variety of Petri net concepts, techniques, and methods as well as various tools and tool environments has been developed to support the process-driven system development. But, system development under the use of Petri nets is still difficult since the one which best fits the application cannot be identified easily. In this paper an application-oriented assistance approach is introduced which helps application developers to find the “right” Petri net variant, tool, technique, and development method for specific development tasks. It is based on the ≫Petri Net Baukasten≪, more especially on its Application Developer View and its Common Base. Both are explained in detail.