SAHRA is an extension for the popular Sparx Systems Enterprise Architect™ UML/SysML modeling tool, which enables practitioners to adopt the hazard analysis method "System Theoretic Process Analysis" (STPA) for their engineering and analysis processes.

STPA, which has been developed by Nancy Leveson at MIT, specifically adresses risks which are generated by functional interaction between control units present in a system. As a result, STPA is especially suitable for analysis of software-based socio-technologic systems. Consequently STPA does not treat safety as a (component) failure problem but as a control problem: Understanding how a system can enter an unsafe state requires understanding which unsafe control actions can occur and why and how they occur.

The SAHRA Enterprise Architect™ extension is developed in a cooperation between the Safety-Critical Systems Research Lab of the Zurich University of Applied Sciences and industrial partners.


While some of the modules and features of SAHRA are in internal and external beta-testing others are still in development.

We have therefore until now provided demo versions solely to strategic partners. Please contact us for further information or to be notified about the software's availability.