SWAT is available for Windows, Mac OS X an Linux platforms. It can be downloaded from https://github.com/iig-uni-freiburg/SWAT20

Installation of Prism
The evaluation of security patterns for Petri-Nets is done using the freely available, highly optimized model checker PRISM. This model checker is able to detect if a given business process model satisfies a given security pattern and provides credible profound results about its findings. Prism is available from: http://www.prismmodelchecker.org/