CURRENT ISSUES OF FUNCTIONAL SAFETY AND CYBERSECURITY ANALYSIS OF INDUSTRIAL AND CRITICAL INFRASTRUCTURES

Abstract

This article addresses some functional safety assessment procedures with cybersecurity aspects in critical industrial installations with regard to the functional safety requirements specified in standards IEC 61508 and IEC 61511. The functional safety management includes hazard identification, risk analysis and assessment, specification of overall safety requirements and definition of safety functions. Based on the risk assessment results, the safety integrity level (SIL) is determined for consecutive safety functions. These functions are implemented within the industrial control system (ICS) and/or the distributed control system (DCS) that consists of the basic process control system (BPCS) and/or the safety instrumented system (SIS). The determination of the required SIL related to the required risk mitigation is based on the semi-quantitative evaluation method. Verification of the SIL for the considered architectures of the BPCS and/or the SIS is supported by probabilistic models with appropriate data and model parameters including cybersecurity related aspects. The proposed approach is illustrated on the example of critical industrial installations.

Keywords

• cybersecurity
• functional safety
• safety integrity level
• security level
• evaluation assurance level
• industrial control system