The Escota's "SINERGIE" project : a hierarchical multicriteria evaluation process over finite scales for maintenance activities
Résumé
The Escota Company, founded in 1956, is the leading operator of toll motorways in France. Due to its integration into the Provence-Alpes-Côte d'Azur region, Escota is committed, as every motorway operator, to a sustainable development approach, including the social, economic and environmental aspects of its activities. Maintenance of the 459 km long motorway network does not simply concern the carriageway and its vicinity : Escota also manages more than 1,900 ha of open spaces ... Every year, specific initiatives are undertaken, or repeated, to include the motorway network in a sustainable development approach : prevention of fire risks, of water pollution risks, but also protection of roadside residents against noise or consideration of rare plant and animal species, management of acquired land along the motorway. Within this scope, the Escota Company thus aims at the formalization and improvement of the decisional process for preventive maintenance and patrimony management in a multi actors and multi criteria (MC) environment. These decisions concern upkeep, improvement and upgrading operations. According to available pieces of knowledge on the patrimony condition, operations are to be planned with regards to the technical but also to the conformity, security and financial criteria. The operations are related to operating domains such as structures, carriageways, road signs and road markings, buildings, prevention of fire risks, open spaces... Managing such a complex patrimony necessitates a dynamic Information Processing System (IPS) to facilitate the way decision-makers use their reasoning capabilities through adequate information processing procedure. The information processing used by Escota patrimony management can be formalized as the following sequence of risk analysis. Periodic inspections are performed to detect and measure any malfunction symptoms as early as possible. The expert in charge of a domain then analyses these technical diagnosis and evaluates the situation seriousness. The official in charge of the operating network coordinates and ponders the experts' needs and requirements. Each actor of this information processing system participates to a tripartite MC decision-making (DM) logic: measurement, evaluation and decision. To each step of this process corresponds a specific set of criteria and an aggregation operator: seriousness of a malfunction results from a prescribed aggregation of the symptoms quotation ; the expert's interpretation of the diagnosis associates an emergency degree to the corresponding maintenance operation with regards to the criteria relating to his operating domain (technical risks assessment); finally, the manager attributes a priority degree to the operation on the basis of a set of more strategic criteria (strategic risks analysis). This hierarchical MC evaluation process enables to breakdown the DM into elementary steps. Each step collaborates to the enrichment of information from measures to priority degrees and thus contributes to the final step, i.e. operation planning. The IPS, presented in this paper, implements this hierarchical DM process to clear up the MC evaluation phases. The Macbeth method is used to support the aggregation operator identification. The IPS automates the elucidation of MC evaluations through the notion of marginal contribution of a criterion and provides traceability functionalities for strategic choices and logical argumentation