The potential for losseshuman, environmental, and financialwith these computer-controlled systems makes quality of paramount importance. The center of gravity of software engineering research in general may now have shifted to Europe.
Software is continually changing and evolving, not only because of the discovery of latent errors, but primarily because of changes in the operating environment, in the needs of the end users, and in the underlying technology.
We need more research on procedures to identify software-related hazards, to eliminate and control these hazards through design, to apply safety-analysis techniques during software development to provide confidence in the safety of software and to aid in the design of hazard protection, and to evaluate the effectiveness of the analysis and design procedures to assess the level of confidence they merit.
One answer to this question is that we have made progress, but the problems we are facing are increasing at a faster rate.
One of the roadblocks in making progress on these problems is the lack of scientifically established information upon which to make decisions about the design of software engineering tools and techniques. Simply replacing the human by computers, the obvious and often only approach considered, may not result in the most efficient, useful, and safe systems.
Independent efforts to ensure individual qualities in narrow domains, e. The [aerospace] industry is being transformed from dependence on traditional manufacturing into something that looks more like IBM and Microsoft with wings.
The methodologies must also incorporate models that are closely related to the problem domain and the way that application experts think about their problems, not necessarily the way that researchers look at the problems.
We need to provide more affordable and effective testing while at the same time exploring the potential for static analysis of important properties and understanding the interaction between these two approaches to assurance.
As the systems we wanted to build became too complex or too time-critical to be controlled by humans or even electromechanical devices, computers started to be used to take over at least part and sometimes all of the control functions.
The EEC countries and the Japanese are catching up and may be ahead in achieving high quality levels. This white paper discusses the problem being attacked, attempts to delineate why the problems have not already been solved, and suggests some specific research topics that we feel are of critical importance in stretching the current limits of complex system engineering.
One of the reasons for the problems is that these systems require that standard engineering techniques be extended to deal with new levels of complexity, new types of failure modes, and new types of problems arising in the interactions between components.
However, no approach exists that combines diverse techniques into an integrated methodology for developing and maintaining software for critical systems. Human-Computer Interaction Most complex systems require a combination of human and computer control, where humans provide intelligence and problem-solving ability while computers handle aspects requiring speed and computational power.
Software reliability is defined as compliance with the requirements specification, but accidents most often occur as a result of flawed specifications, i.
Sometimes decisions will have to be made not to change critical software if the risk is unwarranted. Often the result of research is methodologies that cannot be incorporated into practice by developers and maintainers.
Specific Areas for Research We believe the following areas are of special importance and difficulty in engineering complex, computer-controlled systems and thus are appropriate avenues of research.
Furthermore, the methodologies that are developed must be usable by other than their developers and must be able to be incorporated into practice by software developers.
We are able to execute and test only a small fraction of the possible system states before software is put into operational use. We need ways to make those decisions, ways to design and construct software so that it can evolve over time without compromising critical properties, and techniques to aid in the evolution and change process itself.
Instead, mathematical models must be used to verify certain required properties. Virtually all non-trivial software has errors in it, and we do not currently have the capability to locate and correct these errors. The desired end is a partnership between the computer and the human that is superior to either of them working alone.
Many techniques can be found to attack particular subproblems, but these techniques may not be easily integrated or may be too costly if very different procedures are required for each critical property or if each part of the software development process does not build on the results obtained in the previous steps.
But we cannot blame all our limitations on increasing expectations. In a slightly different context, a better understanding also is needed of the way to design software engineering tools and languages in order to minimize the number of errors that are introduced during software development and to provide usable and useful tools to software developers.System Safety and Software Safety Research.
The methology includes special management structures and procedures, system hazard analysis, software hazard analysis, requirements modeling and analysis for completeness and safety, design for safety, design of human-machine interaction, verification (both testing and code.
White Paper An Introduction to Safety quality system for software with a safety integrity level of 0, and an essential prerequisite for higher integrity levels. IEC A general standard, which sets the scene for P a g e | 8An Introduction to Safety Critical Systems.
The Software and System Safety Research Group is a response to these problems. It's goal is to act as a focus for interdisciplinary research, education, and development to support the engineering and use of computers embedded in and controlling complex engineered systems.
Software System Safety defines the safety requirements for software developers and assures the implementation and compliance with those requirements. APT's Software System Safety Process A proven software safety program, this process is successfully applied to major DoD programs.
MRI-NSSI\ White Paper Module 3 1 SafetyAnalyst: Software Tools for Safety Management of Specific Highway Sites White Paper for Module 3—Economic Appraisal and Priority Ranking August 1.
INTRODUCTION countermeasures are based on the best available safety research. The analyses include. Download – Safety Management Software White Paper.
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