Integrated application of compositional and behavioural safety analysis

Safety critical systems are systems whose operational deviations can potentially lead to catastrophic consequences or loss of human lives. These systems are widely employed in various industries, including the automotive, aerospace, weapons and nuclear industries. Today‟s modern safety-critical systems often incorporate numerous embedded control components, involve various engineering disciplines, and employ distributed architectures and complex communication structures. In such systems, achieving design solutions that fulfil safety requirements remains a challenge. Classical safety analysis techniques such as Fault Tree Analysis (FTA) and Failure Modes and Effects Analysis (FMEA) are popular techniques employed to predict the safety of such systems. However, these techniques are traditionally manual, and in the context of a complex system become difficult, laborious, expensive and error-prone. This limitation results in the FTA and FMEA performed only at the later stage of lifecycle when the design has been finalized. This late contribution means that results from the process miss the opportunity to influence system design, which could incur extra cost and effort in late design modifications. Challenges also arise in the lack of systematic methods to capture and manage design models and safety artefacts as in traditional practices, system design models and safety analyses are often handled separately. With these drawbacks, classical safety analysis techniques face tremendous challenges and are no longer deemed to be sufficiently effective and robust in managing the rising intricacy of modern complex design. Model-Based Safety Analysis (MBSA) has been proposed in the recent years to address some of these problems. Focus has been placed on developing more-effective and robust safety assessment techniques through automation of the synthesis and analysis process. MBSA introduces semi-formal and formal models in the centre of the design and assessment process. Effort is focused on the construction of the formal specification of the system model. This specification model is subsequently used as