Maintenance Scheduling of Traffic Light System in Case of Resource Unavailability.

Due to the increasing number of users of urban roads, congestion and insecurity are a major problem faced by cities, today. To this end, the reliability of road signs has become a crucial concept that combines security and traffic control. This article focuses on the problem of reordering the medium-term maintenance tasks of an automatic signaling system in the event of resource unavailability. The studied system is a remotely controlled centralized system, whose facilities are distributed across multiple sites. We are specifically interested in the case of the existence of a mobile maintenance entity which intervenes in replacements on multiple sites, according to a predetermined scheduling. However, this scheduling suffers from hazards related to resource unavailability. Our goal is to provide the signaling system with the appropriate tools to prevent these contingencies. For this, we propose a methodology based on the use of time Petri nets (TPN) for modeling traffic light system studied, and the use of timed automata (TA) for analysis and synthesis of results. Thus, we will be able to reschedule maintenance tasks in case of unavailability of resources.