Towards Safety Assessment Checklist for Safety-Critical Systems

Safety-critical systems are ever increasing in day to day life such as use from microwave oven to robots involving computer systems and software. Safetycritical systems must consider safety engineering and safety management principles in order to be safe when they are put into use. Safety analysis must be done. Safety assessment of such systems is difficult but not impossible. They must deal with the hazards analysis in order to reduce or prevent risks to environment, property damage and/or loss of life through risk-free and failure free or fail-safe operations. The existing methods are found to be limited and inadequate to address the risks associated and for safety assessment. This paper proposes a methodology for safety assessment of safety critical systems based on identifying significant and non-significant aspects of risk. The methodology considers various contributions towards risk and safety assessment. The methodology reviews existing risk categories and classification. This paper also presents a set of risk contributing factors and significance denoting function. A case study of typical power plant operations for safety assessment is presented to validate proposed methodology. The methodology provides clarity to improve safety of safety-critical systems. This paper also discusses about the scope of automation. The results indicated that substantial increase in risk ranking with the proposed methodology to that of existing risk ranking indicating the safety assessment.