Requirements engineering of industrial automation systems: Adapting the CESAR requirements meta model for safety-critical smart grid software

Requirements engineering is the first stage in the development of any system. For safety-critical industrial systems like smart-grids, we must ensure that requirements are properly elicited, defined, analyzed and managed. This paper adapts the requirements framework developed in the CESAR European project, called the CESAR requirements meta-model, to support all aspects of requirements engineering for safety-critical systems. This enables the formalization of requirements in order to automate and assist in many aspects of later stages in the system development life cycle. Using a smart grid system from the FREEDM project, we illustrate that the adapted requirements engineering framework is comprehensive and rich for large safety-critical systems. We find that the use of the IEC 61499 function block standard provides an appropriate system modelling and implementation framework, which complements the strengths of the proposed requirements engineering framework. Traceability links between requirements and components of an IEC 61499 system model can help with automatic test case generation and formal analysis of requirements.