There is an increasing interest in acquiring commercial-off-the-shelf (COTS) functionality for safety-critical applications. However, the selection of COTS products for such applications is still carried out in an ad hoc manner. This creates great difficulties for realistic cost and effort estimation, integration of the selected COTS product, and the certification of final COTS-based safetycrit...

This paper defines a constrained Artificial Neural Network (ANN) that can be employed for highly-dependable roles in safety critical applications. The derived model is based upon the Fuzzy Self-Organising Map (FSOM) and enables behaviour to be described qualitatively and quantitatively. By harnessing these desirable features, behaviour is bounded through incorporation of safety constraints – de...

The development of mixed-criticality systems that integrate applications of different criticality levels (safety, security, real-time and non real-time) can provide multiple benefits such as product cost-size-weight reduction, reliability increase and scalability. However, the integration of applications of different levels of criticality leads to several challenges with respect to safety certi...

System safety research has a weakness in terms of evaluation. In particular, the field has a poor track record for applying appropriate research methods to the questions we wish to answer, and for evaluating the answers in a convincing way. Given changes in government and public attitudes to research funding, this will be an increasing concern in the near future. In this paper, we define a taxo...

The integrated EU-project DECOS (Dependable Embedded Components and Systems) aims at developing an integrated architecture for embedded systems to reduce life-cycle costs and to increase dependability of embedded applications. To facilitate the certification process of DECOS-based applications, the DECOS Test Bench constitutes a framework to support Validation & Verification. By implementing a ...

Different theories and applications concerning "safety barriers" and "safety functions" have been investigated. The general aim was to compare principles and terminology in some different areas. Of special interest are applications from the nuclear and chemical-process industries, and a short summary is given. The study is based on a literature review, interviews and discussions. Only a few the...

Safety applications in vehicular ad hoc network (VANET) are handled by broadcast to disseminate safety related messages, due to lack of stable topology. The mobility of vehicles leads to significant performance degradation, especially in dense and dynamic scenarios. This paper presents an information theory based mobility model to determine the theoretical amount of information for VANET safety...

Safety cases are now regularly used to communicate the argument about the achievement of acceptable levels of safety for safety critical systems. Increasingly, safety standards such as Defence Standard 00-56 require the scope of the safety case to cover not only the development of the system, but also operating and maintenance through life, including decommissioning. This involves two dimension...

In previous papers, we asserted that software system safety is primarily concerned with epistemic questions, that is, questions concerning knowledge and the degree of confidence that can be placed in that knowledge. We also enumerated a set of 21 foundational epistemic questions, discussed some of the difficulties that exist in answering these questions adequately today, and speculated briefly ...