The standardized generation and the robust filtering of the command as tools of optimization of the mental workload of the systems engineer. Raphaël Coupat 1&2 , Marc Meslay 1 , Marc-Axel Burette 1 , Alexandre Philippot 2 , David Annebicque 2 , Bernard Riera 2 raphael.coupat@univ-reims.fr 1 IGTE (CES), Direction de l’Ingénierie, Société Nationale des Chemins de Fer Français, 6, avenue François Mitterrand – 93574 La Plaine Saint Denis CEDEX, France 2 CReSTIC (EA3804), Université de Reims Champagne-Ardenne Moulin de la Housse, BP 1039, 51687 REIMS Cedex 2, France Abstract: This paper presents an original approach to standardize the work of electric traction of railway transportation. This approach is developed within an industrial thesis, financed by the SNCF (French acronym for National Society of French Railways) in association with the CReSTIC (Research Centre in Information and Communication Science and Technologies). This approach is composed of two axes. The first axis is the standardized generation of deliverables made by the systems engineers in order to help them keeping their concentration on cognitive task and to avoid repetitive tasks which can lead to mental underload. The second axis is the integration of a robust filter is based on the use of safety constraints within the methodology of standardization. This controller is then constrained by the functional programs, already established and used by the SNCF. The systems engineers can be serene and this filter avoids the stress of decision-making which can lead to a mental overload. Keywords: control, task-based design, mental workload, standardization process, safety-critical systems, railway transport. 1. INTRODUCTION The French national rail network (RFN) has to face the competition of the European rail transportation, due to the opening of the market. In order to keep its leadership of the French rail market, SNCF (French acronym for National Society of French Railways) tries to set up innovative solutions improving the productivity. These solutions must not be to the detriment of the safety of installations and persons from which the engineering of the SNCF infrastructure is a guarantor. In SNCF, the electric traction engineering (IGTE) is in charge of the specification of the equipment of telecontrol, automation and Low Voltage (LV) protections of the Power Supply Equipment of the Electric Lines (PSEEL) market. To improve productivity and performance, IGTE implements solutions harmonizing the working environment of the telecontrol, automation and LV protections design studies, realized on the PSEEL, as specialized project management. Suggested solutions must also be a way to ensure the safety of PSEEL as presented in this article. The PSEEL are the electrical supply points of the electrified lines, called catenary. The role of the PSEEL is to transform, to supply, even to rectifier in the case of DC supply, the tension of the High-Voltage (HV) network into compatible tension with traction units (1500 V DC or 25 kV AC). These electrical systems, under (very) High-Voltage, are subjected to strict standards of railway safety (EN 50126). The PSEEL are distributed automated systems among which control- command can be done locally but also remotely, in a centralized control station (Gilmore et al., 1989) called Central Sub-Stations (CSS). The human supervisors (Fig. 1) can activate HV devices (switches, circuit-breakers…) since this control room. They are responsible for ensuring the supply of PSEEL under nominal and degraded modes (maintenance of catenary voltage) to ensure safety when working on PSEEL or catenary under national regulations (UTE C 18510) or specific and emergency shutdown in case of electrical danger to persons and properties. The approach integrates two axes of improvement (Fig. 1). The first one is the standardization, in order to improve the homogeneity of deliverables made by the technical studies. Standardization can also integrate the generation of deliverables (documents, schema...). The deliverables generation allows optimizing the working time of the systems engineers by avoiding them to enter redundant data. The improvement of the working conditions involves a regulation of their mental workload by avoiding the errors consecutive to the mental underload and to the peaks of overload. The second one is the implementation of a robust filter based on safety constraints (Riera et al., 2012) to ensure the safety of persons and PSEEL whatever is the functional control implemented in Programmable Logic Controller (PLC). This control safety filtering should be used to prevent control errors that may be sent from CSS. This solution is based on the principle of unique data entering, this allows optimizing the workload. The description of the PSEEL in this unique software environment should allow generating all deliverables (documents, programs, wiring diagrams ...). This software solution must be a part of a process of work standardization.