Tool support for creating FMC* diagrams [Block diagrams, Petri nets, Entity-Relationship diagrams (ERD)] in MS-Visio 2000 and newer. Features: stencils, consistency checking, Petri net simulation, exporter e.g. pdf, ... *Fundamental Modeling Concepts
A stripped down version of the stencil set is available for TAM (Technical Architecture Modeling of SAP).