Modeling Controller Tasks for Safety Analysis

As control systems become more complex, the use of automated control has increased. At the same time, the role of the human operator has changed from primary system controller to supervisor or monitor. Safe design of the human{computer interaction becomes more di cult. In this paper, we present a visual task modeling language that can be used by system designers to model human{computer interactions. The visual models can be translated into SpecTRM-RL, a blackbox speci cation language for modeling the automated portion of the control system. The SpecTRM-RL suite of analysis tools allow the designer to perform formal and informal safety analyses on the task model in isolation or integrated with the rest of the modeled system.