Design for safety: proposition of a model to detect hazards through energy flows analysis

Abstract

The European directive 2006/42/CE promulgates the machine safe design principles to prevent professional risks. However, outside machines that have specific safety standards, the designers of special machines and manufacturing systems can only use generic safety standards, limiting as a consequence the results of hazards detection. The aim of this paper is to present an original approach for this detection during the design of working equipment. We based our study on a hypothesis of the literature that links hazards to the presence of energy flows. Thus, the hazards detection is reduced to the study of the building of energy flows and the detection of potential links between these flows and the operator. Thanks to such data, the designer will be able to select the best risk prevention solutions. To reach this goal, we decided to use the Functional Energetic Model (FEMo) to model the technical system and its energy flows. This choice was made because this model was developed for the design of technical systems integrating different types of energy. By using this modelling, the designer can easily analyses every potential interactions between the energy flows and the operator, depending on the future working situations in each life cycle phases. Our approach builds on this model all along the design process, allowing the designer to early detect hazards and to apply at the best moment the risk prevention solutions. We present the application of this approach during the design of a working equipment, since the definition of the raw need. We confirm that its application and the system modelling in the EFM formalism are possible since the conceptual design phase. Data from the next design phases enrich the model, and consequently improve the detection and characterization of hazards.