A Systematic Literature Review on RAMS analysis for critical infrastructures protection

Reliability, Availability, Maintainability, and Safety/Security (RAMS) analysis of Critical Infrastructures (CIs) can be applied to investigate their performance subjected to failure modes. The literature has witnessed earlier research approaches to RAM analysis. However, the integration of cybersecurity or safety aspects, along with the RAM to develop RAMS analysis methods, tools, and models, is a significant aspect for protecting CIs as their digitalization is progressing. In recent times, digital components and systems comprising information and communication technologies, smart devices, efficient gateways, faster protocols have transformed the CIs. This transformation comes with a considerable cost, such as the necessity to integrate innovative cyber-defense measures and policies due to new vulnerabilities, efficient maintenance strategies, risk management scenario development, resilience with self-healing architecture. Nevertheless, the current knowledge body lacks an up-to-date Systematic Literature Review (SLR) focused on addressing integrated protection aspects, recent developments, and evaluation criteria towards RAMS analysis for CIs. Accordingly, this study aims to provide a comprehensive SLR on existing studies dealing with developing techniques, methodologies, protocols, models, and RAMS analysis tools for different applications. This SLR followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. 1513 records published between 2011 and 2020 are initially identified, which are later screened to 212 records to be considered for the eligibility check process. Finally, after examining the exclusion and inclusion criteria, a total of 19 articles are included in this research. In this SLR, a comparative analysis of existing solutions based on included studies is presented in different aspects such as developed architectures and methodologies, performance evaluation mechanisms, implementation scenarios, targeted applications, pros and cons, and applied CIs protection aspects associated with RAMS. The findings suggest that RAMS analysis for CIs is an emerging research area, with currently focused applications including power grid stations, Cyber-Physical Systems, cloud computing, maritime transportation, and Industrial Control Systems. 36.8% of the studies have performed a real-time implementation, while the remaining approaches have either performed simulation or preliminary analysis. Also, 84.2% of the included studies focus on integrating only three aspects of CIs protection. Finally, the open research challenges and limitations of existing studies and their respective emerging solutions are presented.