A Case Study in Fault Tolerance and Software Safety

该项目涉及在开发安全关键计算系统时出现的安全和容错问题。在许多计算机应用中，安全而不是可靠性或可用性是压倒一切的问题。只要不造成损害，此类系统的功能减少或更改都是可以接受的。理论研究将集中在软件生命周期的规范和设计阶段。具体地说，该项目将制定一个安全定义框架，在该框架内确定软件工程师的责任，并设计软件架构以支持安全软件的开发。它将调查是否有可能利用一种增强形式的软件重复使用，以促进安全软件规范和设计的快速发展。实证研究将集中在一个案例研究上，该案例研究将涉及一个实验性安全关键医疗设备的软件的某些方面。这种设备被称为磁性立体定向系统，是治疗脑部疾病的各种形式的新方法。将制定软件安全规范，并建立原型。将构建由从案例研究派生的少量部件填充的重用库，并在后续的重用技术研究中使用。

This project involves safety and fault-tolerance problems raised in the development of safety-critical computing systems. There are many computer applications in which safety and not reliability or availability is the overriding concern. Reduced or altered functionality of such systems is acceptable as long as no harm is done. Theoretical research will focus on the specification and design phases of the software lifecycle. Specifically, the project will develop a framework of definitions of safety, establish the responsibility of the software engineer within that framework, and design software architectures to support the development of safe software. It will investigate the possibility that an enhanced form of software reuse can be exploited to facilitate rapid development of specifications and designs for safe software. Empirical research will focus on a case study which will involve certain aspects of the software for an experimental safety-critical medical device. The device, known as the Magnetic Stereotaxis System, is a new approach to various forms of therapy for brain disorders. Software safety specifications will be constructed and a prototype built. Reuse libraries populated by a small number of parts derived from the case study will be built and used in subsequent studies of reuse technology.