HAZOP-UML is part of model-based safety analysis (MBSA) tools, dedicated to hazard analysis mixing UML (Unified Modelling Language) and HAZOP (Hazard Operability). You will find complete description of the approach in the publications (see menu / Publications).
The tool is no longer supported, but the method has been transferred in industry (e.g., STERELA in France) and used in several research projects (e.g., FP7-SAPHARI: Safe and Autonomous Physical Human-Aware Robot Interaction (2011-2015) – European Project, or ANR-MIRAS: Multimodal Interactive Robot of Assistance in Strolling (2009-2013).