This presentation focuses on the problematic of operation sequences generation for complex and critical systems. The main objective is to safely operate some actions on the process devices (mainly actuators), according to safety requirements specifications. An evaluation of a joint approach mixing an ISA88-based approach for models structurationn, and a components behavioral modeling using communicating automata, this prensentation shows both feasibility and limits of an automatic approach for the generation of safe operation sequences based on reachability analysis.