Formalisation of normative knowledge for safe design

This paper presents a formal methodology for modelling knowledge included in safety standards. The use of the NIAM/ORM method addresses the problem of unprecise semantics and the misinterpretation introduced by the use of natural languages. It also allows for producing a formal model of the knowledge. This formalisation is a necessary step in order to exploit the knowledge efficiently, but is not sufficient in itself. So, we propose to restructure the normative knowledge, basing this restructuring on a generic structure of engineering views. This multi-criterion approach allows the designer to use standards much easier in this form than in their current textual expression. Furthermore, the resulting formal model of a standard can be implemented. This implementation results in the production of a Computer Aided Safety Standards Application for design (CASSA) tool. This tool allows to analyse various application scenarios, all included in the safety knowledge model, through specific user-oriented interfaces depending on each user's objective. Nevertheless, the implemented model of the safety knowledge is independent and unique with regard to these scenarios. In so doing, our contribution can concern users other than machine designers, such as valuers, standardisation experts or teachers, as well as relate to other areas dealing with standards such as the environment, toy industry, etc.