Toward a Petri Net Based Approach to Support Risk Analysis of Dissonances between Human and Machine

Autonomy of a system is defined by its knowledge, its availability and its prescription to achieve goals. Different conflicts may occur between these parameters. They are called dissonances and the paper focuses on conflicts between individual or collective knowledge related to a predefined task allocation. Two kinds of dissonances will be studied: affordances and inconsistencies. Affordances relates to knowledge discovery when new links can exist between goals and conditions to achieve goals. Inconsistencies occur when opposite goals can be achieved in a given operational context. Contradictions concern individual inconsistencies related to the knowledge content of a decision-maker. Interferences are inconsistencies between the prescriptions of different decision-makers. The mathematical formalism of the Petri Net is then adapted to identify automatically affordances and inconsistencies. Knowledge is modeled by Petri net implementing the goals, the conditions of activation of a goal and the links between the goals and the conditions, taking into account the elements of interactions and the prescriptions of the decision-makers. The approach is applied to transportation domain by identifying possible affordances by using existing elements of interactions for achieving new goals, or by identifying inconsistencies between human drivers and on-board assistance systems.