Читать книгу Root Cause Failure Analysis - Trinath Sahoo - Страница 42

One of the important steps in root cause failure analysis (RCFA) is to define a problem. Effective and event descriptions are helpful to ensure the execution of appropriate root cause analyses. The first step to define the problem is by asking the four questions:

 What is the problem?

 When did it happen?

 Where did it happen? and

 How did it impact the goals?

The investigator or the RCA analyst seldom present when an incident or failure occurs. Therefore, the first information report or FIR is the initial notification that an incident or failure has taken place. In most cases, the communication will not contain a complete description of the problem. Rather, it will be a very brief description of the perceived symptoms observed by the person reporting the problem.

It involves failure reporting regarding incident which includes details of failure time, place, nature of failure, and failure impacts on organization.

Consider a problem on a centrifugal pump AC Motor. A typical problem report could state “pump ABC motor has a problem”. Even though this type of problem reporting could be worse, for example, “fan is bad” or “shrill noise from one of the pumps.” “Pump ABC Motor has a problem” it is still not a very good definition.

A better definition may be “AC Motor of pump ABC” is hot. Can we do better with some basic Root Cause Analysis steps? Sure! Let’s ask the traditional, WHAT, WHERE, WHEN, EXTENT. The problem is:

What: AC Motor of pump ABC (already answered) Where: Motor is hot close to the front (belt drive side) When: Don’t know exactly, but 7 days ago a 138 F reading was recorded (normal) Extent: Front of motor is running 210 F.

The above definition is usually enough to get a problem started. Is it ideal? Perhaps not, but it’s pretty good for a problem statement. This level of problem reporting for craftspeople and operators would be a huge improvement for most plants in improving day‐to‐day Root Cause Analysis.