Concern for safety permeates every level of the system design, and must be addressed at each stage of study, development, and deployment. The second section of the Safety Analysis discusses the importance of developing a system safety program that consists of safety-related activities in the planning, design, construction, deployment, and operations phases of AHS projects. The topic includes an overview of hazard analysis methodologies and the stages in the program life where each analysis method is applicable. System safety emphasizes the verification and demonstration of the overall safety of the system as implemented for subsequent long-term operation. Identification of safety as a system-level issue and establishing design practices and standards at the outset of the development phase are important steps toward creating a system that will meet the safety design goals.
Safety is an important concern at the subsystem design level.
Safety can be improved by introducing higher levels of subsystem redundancy, but this tends to increase system cost out of proportion to the benefit. Improving component reliability and providing cross-functionality among subsystems may yield higher safety benefits at lower overall cost. AHS can use existing vehicle subsystems such as engine controllers or ABS as models for reliable, cost effective, safe implementation. The effect of the system architecture on the cost of safe system design will be a primary consideration in the flowdown of subsystem functionality. A related area of study is identifying specific hazards or failure modes that are generic to the system architecture, and consequently apply uniformly to each of the representative system configurations used in this analysis.