Software Safety in Process Control Systems

本研究的目的是开发一套集成的技术来提高过程控制系统的软件安全性。相关类型的软件包括监视和控制飞机和其他运输工具、核电站、医疗设备、制造过程以及航空航天和国防系统的软件。虽然系统安全工程师已经制定了处理物理系统危险的程序，但计算机控制的引入给系统工程师和软件工程师带来了新的和未解决的问题。本研究的基本方法包括在整个软件开发中应用软件危害分析和危害控制技术，将它们与系统工程师在系统级别并行执行的系统危害分析和控制程序联系起来。信心是通过使用保护层来实现的：软件安全验证和分析是通过使用软件安全设计过程来支持的，这些过程可以防止由于未检测到的软件故障（包括软件需求规范中的缺陷）而导致的危险状态。两者都有外部硬件保护备份。

The objective of this research is to develop an integrated set of techniques to enhance software safety in process control systems. Examples of relevant types of software include that which monitors and controls aircraft and other means of transportation, nuclear power plants, medical devices, manufacturing processes, and aerospace and defense systems. Although system-safety engineers have developed procedures to deal with hazards in physical systems, the introduction of computer control has created new and unsolved problems both for system engineers and software engineers. The basic approach in this research involves applying software hazard analysis and hazard control techniques throughout software development, linking them to the system hazard analysis and control procedures that are being performed in parallel by the system engineers at the system level. Confidence is achieved through the use of layers of protection: The software safety verification and analysis is backed up by using software safety design procedures that protect against hazardous states resulting from undetected software faults, including flaws in the software requirements specification. Both of these are backed up by external hardware protection.