Failure Mode and Effect Analysis (FMEA) is a method for assessing cause-consequence relations between component faults and hazards that may occur during the lifetime of a system. The analysis is typically time intensive and informal, and for this reason FMEA has been extended with traditional model checking support. Such support does not take into account the probabilities associated with a component fault occurring, yet such information is crucial to developing hazard reduction strategies for a system. In this paper we propose a method for FMEA which makes use of probabilistic fault injection and probabilistic model checking. Based on this approach safety engineers are able to formally identify if a failure mode occurs with a probability higher than its tolerable hazard rate.

The Real-Time Specification for Java (RTSJ) is a set of interfaces and behavioural specifications that allow for realtime programming in Java. It is designed to support both hard and soft real-time applications. Among its major features are: scheduling properties, asynchronous event handling, asynchronous transfer of control and enhanced memory management. Since the release of the RTSJ, many implementations have been developed conformant to this specification. Their performance on certain aspects of the RTSJ can vary greatly. For real-time programmers it is important to highlight these variations so that the most suitable implementation is chosen for the application being developed. This paper evaluates the performance of two commercial releases according to specific features of the RTSJ. The two implementations we choose are Java RTS (Java Real-Time System) from Sun-Microsystems and JamaicaVM from Aicas which are both widely used in academia and industry. Efficiency and predictability, which are important considerations when designing a real-time application, are considered. Specifically, the features analysed are: memory allocation, thread management, synchronisation and asynchronous event handling. This evaluation will benefit the development and improvement of future RTSJ implementations.

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