ADVANCED MATERIALS & PROCESSES | MARCH 2026 24 As previously stated, a problem- solving process must be tailored to address the specific issue and failure mode(s) and mechanism should be identified before attempting to deter- mine the source of the failure. This necessitates that the first steps in the failure investigation are not only to identify and understand the failure mode and mechanisms, but to also ask numerous questions to fully understand the nature and scope of the issue. To be more specific, one must completely understand the problem before trying to solve it. The 8P Failure Investigation Process was created by the author as a very specific set of tasks to keep the investi- gation on track and focused on finding the TRC of the failure. The process provided a systematic method to ensure that the TRC of the failure could be identified, documentation of the investigation collected and retained, results of the investigation properly reported, and corrective action implemented. The process additionally and most importantly helped keep the investi- gation focused on what needed to be accomplished and in a logical sequence. The specific steps in the process are shown in Table 2. A review of Table 2 reveals that there are actually nine steps listed for the process. Step 9, P-0 “prevention” was added after the initial development of the 8P process. This additional step ensures documentation of the corrective and preventive action as a follow up to the process. The reasoning for this procedural revision is explained in the following discussion of the individual process steps. THE 8P PROCESS STEPS P-1 Problem. This initial step in the process requires lots of questions and answers before the investigation is started. Without knowing the exact nature and possible ramifications of the failure, the scope and direction of the investigation cannot possibly be implemented and focused on determining the TRC of the failure. Understanding the problem and issues surrounding the failure goes beyond identifying the failure mode. It focuses on the evidence surrounding, the details leading up to, and ramifications of the failure. The problem identification phase determines the scope of the investigation. Additionally, the implications of and potential legal concerns due to the failure need to be considered. Correctly identifying and understanding the problem is paramount to a successful investigation. This step will lay the foundation for the investigation. The TRC of the failure absolutely needs to be identified, but equally important is the need to understand the consequences of the failure. The investigation must address the true problem and not simply treat symptoms of the issue. P-2 Preparation. This phase of the investigation could well be titled planning. The word preparation was chosen for a very specific reason. Planning is merely a part of the preparation. Nothing worth doing, or effectively accomplished, is done without a plan. Planning is the first step in preparation. The complexity of the problem will dictate the extent of the plan to resolve the problem. the failure mechanism or propagation. The three stages can also be identified as the why, how, and what of the failure event. Figure 1 provides a graphic illustration of the three stages of a failure and the failure investigation process. Note that the failure investigation process is actually the reverse of the failure progression. After a failure has been identified, the failed component or assembly is examined to determine the failure mode(s). Then the investigation proceeds to find evidence of how the failure progressed (failure mechanism). The positive identification of the failure mode(s) and mechanism will ultimately lead to the determination of the TRC “why” (the source) of the failure. UNIQUE ASPECTS OF FAILURE INVESTIGATIONS One of the unique aspects of a failure investigation is that the end result, that is, the failure mode and mechanisms, must be positively identified and understood before the investigation can begin. The investigation process cannot possibly be initiated without that information. This nearly always requires a metallurgist or materials engineer. Additionally, all metallurgical failures are unique in that the circumstances that precipitated the failure are specific to the case being investigated. This requires an in-depth investigation into the conditions surrounding the failure and events leading up to the failure. THE 8P FAILURE INVESTIGATION PROCESS Most of the failure investigations the author has performed over his career have been fairly routine. None were as complicated as an aircraft crash or similar catastrophic event. However, some were very complex failure investigations. After leading many investigations and compiling subsequent reports, it became evident that the same process and methodology were typically utilized for very simple failures as well as the complex investigations. The main difference was the scope and depth of the investigation. TABLE 2 — THE 8P FAILURE INVESTIGATION PROCESS Stage Description P-1 Problem P-2 Preparation P-3 Parts P-4 People P-5 Processes P-6 Photos P-7 Paper P-8 Presentation P-0 Prevention
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