Develop a Safety Assurance approach for Complex Systems (Problem Definition) Supervisors: Tim Kelly, Rob Alexander Chris Leong HISE Group Giving a Presentation - Nov 14

2 Problem Definition With more and more independent entities (systems and platforms) dynamically networking as a complex system to achieve a common purpose (e.g. operation and training), How safe is considered safe enough for such complex system? Is the current way of doing hazard and risk analysis and safety assessment sufficient to analyse such complex system? How can simulation help to make safety assessment of such complex system more effective and efficient? How do we consider the unique characteristics (e.g. adaptive and emergent) of such complex system as part of safety assessment?

3 What is Safety Assurance? Which description of Complex System best describes the problem space? Key Concepts Develop a Safety Assurance approach for Complex Systems

4 HA PSA SSA HA: Hazard Analysis Identifies potential hazards and safety risks of the system PSA: Preliminary Safety Assessment Performs safety analyses as the system is being developed to suggest design and architectural choices to meet safety goals SA: Safety Assessment Verifies compliance of the system architecture with the safety requirements Safety Assurance [Bozzano10] General safety assessment workflow

5 Properties System-of- Systems Open Adaptive Systems Cyber Physical Systems IndependenceYes Geographical distributedYes Emergent behaviourYes Evolutionary developmentYes Interface interactions Yes Complex System Cyber-Physical Systems (CPS) [Shi11] systems that integrate the dynamics of the physical processes with those of the software and communication, providing abstraction and modelling, design, and analysis techniques for the integrated world Open Adaptive Systems (OAS) [Trapp13] systems that dynamically connect to each other (openness) and adapt to a changing context at runtime (adaptive) System-of-Systems (SoS) [Kazman13] Is a set of systems that are cooperating while simultaneously working as independent entities Dynamic of Complex System [Yam97] A complex system is a system formed out of many components whose behaviour is emergent, that is, the behaviour of the system cannot be simply inferred from the behaviour of its components. The amount of information necessary to describe the behaviour of such a system is a measure of its complexity. ….

6 Safety assurance: Leverage on the different phases under the safety engineering practices to minimize the risks of operational hazards (e.g. HRA, PSA, SSSA, certification, awareness). Complex Systems: Intend is not to present a unified definition but to gain awareness of the unique characteristics compared to monolithic systems (e.g. independence, emergent behaviour, evolutionary) Summary