Chapter 4: Nine Steps of a Failure Investigation
This chapter describes the nine steps of a failure investigation. The steps add detail to the problem-solving process introduced in Chapter 3. The first five steps are (1) understanding and negotiating the investigation goals, (2) obtaining an understanding of the failure, (3) objectively and clearly identifying all possible root causes, (4) evaluating the likelihood of each root cause, and (5) converging on the most likely root cause(s). Many failure investigations stop at this point, but significant value is provided in the next four steps, which are (6) identifying all possible corrective actions, (7) evaluating each corrective action, (8) selecting the optimal corrective action(s), and (9) evaluating the effectiveness of each corrective action. Each step is discussed in detail with examples along with information on the procedures to be followed and resources needed for the investigation.