ABSTRACT
Specifications are usually incomplete, even after the attention described in Chapter 2 is paid to them. By the time you apply the information in Chapter 2, you have only the concept design. The next step is to conduct risk analysis to discover new safety-related risks, and therefore add more new requirements. The main tool for risk analysis is the Preliminary Hazard Analysis (PHA). We will go deeper into this most important analysis in this chapter. The other tools for deeper analysis are Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA). These are covered in Chapter 4.
