A Tool-Supported Model-Based Method for Facilitating the EN50129-Compliant Safety Approval Process

Compliance with the CENELEC series is mandatory during the planning of as well as development of railway systems. For compliance purposes, the creation of safety plans, which define safety-related activities and all other process elements relevant at the planning phase, is also needed. These plans are expected to be executed during the development phase. Specifically, EN 50129 defines the safety plan acceptance and approval process, where interactions between the applicant and the certification body are recommended: after the planning phase, to ensure the compliance between plans and standards, and after the development phase, to ensure the effective and not-deviating-unless-justified execution of plans. In this paper, we provide a tool-supported method for facilitating the safety approval processes/certification liaison processes. More specifically, the facilitation consists in guidance for modelling planned processes and the requirements listed in the standards in order to enable the automatic generation of baselines, post-planning processes and evidence models, needed during the execution phase and change impact tracking for manual monitoring of the compatibility between plans and their execution. The applicability of the proposed method is illustrated in the context of EN 50126-1 and EN 50129 standards.