Collaborative Cyber-Physical Systems (CCPS) are systems that contain tightly coupled physical and cyber components, massively interconnected subsystems, and collaborate to achieve a common goal. The safety of a single Cyber-Physical System (CPS) can be achieved by following the safety standards such as ISO 26262 and IEC 61508 or by applying hazard analysis techniques. However, due to the complex, highly interconnected, heterogeneous, and collaborative nature of CCPS, a fault in one CPS's components can trigger many other faults in other collaborating CPSs. Therefore, a safety assurance technique based on fault criticality analysis would require to ensure safety in CCPS. This paper presents a Fault Criticality Matrix (FCM) implemented in our tool called CPSTracer, which contains several data such as identified fault, fault criticality, safety guard, etc. The proposed FCM is based on composite hazard analysis and content-based relationships among the hazard analysis artifacts, and ensures that the safety guard controls the identified faults at design time; thus, we can effectively manage and control the fault at the design phase to ensure the safe development of CPSs. To validate our approach, we introduce a case study on the Platooning system (a collaborative CPS). We perform the criticality analysis of the Platooning system using FCM in our developed tool. After the detailed fault criticality analysis, we investigate the results to check the appropriateness and effectiveness with two research questions. Also, by performing simulation for the Platooning, we showed that the rate of collision of the Platooning system without using FCM was quite high as compared to the rate of collisions of the system after analyzing the fault criticality using FCM.

翻译：协作信息物理系统（CCPS）是包含紧密耦合的物理与计算组件、大规模互联子系统，并通过协作实现共同目标的系统。单一信息物理系统（CPS）的安全性可通过遵循ISO 26262和IEC 61508等安全标准或运用危险分析技术得以保障。然而，由于CCPS具有复杂、高度互联、异构及协作特性，一个CPS组件的故障可能触发其他协作CPS中的多重连锁故障。因此，基于故障关键性分析的安全保障技术对于确保CCPS安全至关重要。本文提出了一种故障关键性矩阵（FCM），并在我们开发的工具CPSTracer中实现，该矩阵包含已识别故障、故障关键性等级、安全防护措施等数据。所提出的FCM基于复合危险分析与危险分析工件间的关联关系，确保在设计阶段安全防护措施能控制已识别故障，从而在设计阶段有效管控故障以实现安全CPS开发。为验证该方法，我们以编队行驶系统（一种协作CPS）为例开展案例研究，利用FCM在开发工具中对其进行关键性分析。完成详细故障关键性分析后，我们通过两项研究问题检验结果的适用性与有效性。此外，通过编队行驶仿真实验表明：与使用FCM进行故障关键性分析后的系统相比，未使用FCM的编队行驶系统碰撞率显著偏高。