Читать книгу Root Cause Failure Analysis - Trinath Sahoo - Страница 116

Depending on the nature of the failure and the availability of physical evidence or background information, there are stages that are common to all successful failure analysis. Steps may be followed by assessment of the damage and conditions leading to failure. These stages may differ depending on whether fracture, corrosion, and/or wear conditions are being investigated.

Generally, a failure analyst will start with a broad range of possible explanations but over time will narrow and refine the existing possibilities. Often, a likely theory develops during the course of the investigation. This can be helpful, but only if the investigator does not let the theory influence his or her objectivity.

The Principal Task of a failure analyst during a physical cause investigation is to identify the sequence of events involved in the failure. Technical skills and tools are required for such identification, but the analyst also needs a mental organizational framework that helps evaluate the significance of observations.

The basic steps are:

1 Collect data

2 Identify damage modes present

3 Identify possible damage mechanisms

4 Test to identify actual mechanisms that occurred

5 Identify which mechanism is primary and which is/are secondary

6 Identify possible root causes

7 Test to determine actual root cause

8 Evaluate and implement corrective actions