Design for Reliability

Chapter 17

Integrating Design for Reliability with Design for Safety

Brian Moriarty

Introduction

Design for safety is a major effort to assure that all known hazards have been considered for a product being designed, and that the hazards are mitigated or acceptable for system operation. In this chapter we address the focus points necessary to assure that a well-designed “acceptable hazard” system will be built. Reliability is a key feature in obtaining the total product base to examine hazards. Previous chapters emphasized the importance of knowing the reliability of the system, the subsystem, and the components of all areas of a product. The safety team utilizes this information in the course of examining a design to insert the reliability data and obtain the risk assessment codes for each hazard found in the design. Design for safety and design for reliability are inseparable. The design project team must work together in the directly compatible use of the information, to reach the conclusion that the design can be used reliably with the hazards defined as acceptable hazards.

The goals of system safety are to have complete knowledge of a system from its original generic design to the final design, with an examination of the hazards that exist, including human errors that may lead to unsafe consequences [1]. Documenting the importance level of each design analysis for safety is a key factor in the history of building a design, and records are kept at each step of the building ...