Software is taking over more and more functionality in most technical systems, which leads to the term software-intensive or cyber-physical systems. Although this offers many exciting new opportunities, it also makes precise analysis of safety and reliability goals much more complicated. Well-known traditional techniques often reach their limits. Model-based approaches on the other hand can be ...

ion of state descriptions. It must be possible to abstract the results of an envisionment so that they can be compared with the descriptions of interesting states. This area is in its infancy, but we would expect it to make a significant contribution to system safety and reliability as it becomes better developed.

This paper describes a framework for assessing the system safety impacts of an Adaptive or Intelligent Cruise Control (ICC) system. This framework incorporates a time-to-collision model that is developed from vehicle headway, speed, and acceleration data that are typically gathered as part of field operational tests. Specifically, the framework combines car-following models with vehicle deceler...

Humans may be viewed as being merely fallible operators of machines; however, that technology-centred view can easily understate the ability of the human to perform tasks which most machines are incapable of doing and to intervene in the event of failure. On the other hand, an overly human-centred view may not take full advantage of the ability of machines to carry out numerically-complex, repe...

NASA has recently instituted requirements for establishing Agency-level safety thresholds and goals that define long-term targeted and maximum tolerable levels of risk to the crew as guidance to developers in evaluating “how safe is safe enough” for a given type of mission. This paper discusses some key concepts regarding the role of the Agency’s safety thresholds and goals in achieving adequat...

By-wire systems have been established for several years in the area of aircraft construction and there are now approaches to utilize this technology in vehicles. The required electronic systems must evidently be available and safe. In the same time the requirements of mass production have to be reached (long life time, long maintainability intervals, low costs, fulfillment of standards). This p...

Covariant types are a powerful language feature for improving type-safety. However, covariant types complicate type-checking when combined with polymorphism. We propose two new language features that can improve type-checking in a language with polymorphism and covariant typing, and also have the potential to improve efficiency as well. Published by Elsevier Ltd.