The Somerset Laboratory is a facility being developed at the University of Virginia that provides a focus for experimental research in safety-critical software engineering. Over the long term, the intent of the laboratory is to establish empirical research with safety- critical systems as a sub-field of software engineering. The laboratory provides the following to researchers World wide, via the Internet: (1) A comprehensive set of artifacts associated with a small number of safety-critical applications that, to the extent possible, describe the applications accurately and comprehensively. There are sufficient artifacts and the artifacts are of sufficient quality that researchers can perform substantial experiments which will be very similar to those that they could be perform if they had direct access to the actual applications. (2) A repository of the results of research projects undertaken using the available applications. This repository contains contributed artifacts, tools, research papers, data files, and contact information. As well as allowing dissemination of results, the repository facilitates cooperative research by alerting researchers to the status, plans, and work of others. (3) A vehicle for accurate comparison of software engineering techniques for safetycritical systems. Using the artifacts associated with the safety-critical applications in the laboratory, researchers are able to evaluate tools and techniques and then compare and contrast different tools and techniques. The comparisons are especially significant in this case because data is obtained by applying them to precisely the same applications. By carrying out experiments using extensive material from actual safety-critical applications, researchers are presented with the complex details of such applications. Dealing with these details helps to ensure the relevance and practical value of the research that is undertaken. In addition, once a solution concept or approach is devised, it can be evaluated (at least in part) by applying it to one or more sample safetycritical applications thus providing a believable assessment. The first safety-critical application that the laboratory has chosen to support is a nuclear reactor. The reactor is a lowpower, research reactor that employs a conventional electromechanical control system. Though a small reactor, it presents significant challenges to researchers interested in softwarebased control and safety systems. The artifacts being developed for the laboratory include details of the reactor's physical structure, the safety rules that must be enforced, digitized images of key elements of the physical equipment, sample traces of all the reactor's sensors, a reactor simulator, and complete wiring diagrams. The goal of this planning grant is to obtain an assessment of the likely level of interest in the laboratory by the research community and to develop a detailed plan for the implementation of the laboratory. ***
