Case Study: Root Cause on Seal Failure in Refinery

Root Cause Analysis represents one of the greatest challenges in reliability program development, requiring a broad understanding of management processes, structured problem solving and behavior. Developing a Root Cause Analysis work process will require effort and persistence as well as new thinking about organizational structure and resource priorities. The potential improvements from developing an effective Root Cause Analysis work process are significant. Most manufacturing processes have opportunities for improvement and cost reduction that have not been obtainable with current efforts. In some cases, these opportunities could represent competitive advantages in manufacturing strategies and processes.

When a bearing in a critical piece of equipment fails prematurely, a maintenance specialist knows the failure usually indicates there is more here than meets the eye. What the untutored eye sees is a failed bearing and little more. However, a premature bearing failure is symptomatic of other problems that, if left untreated, will cause the same kind of failure to occur again.

As a teacher and a practitioner of root cause analysis, I see not only the physical motions of going through such an effort, but also the psychology behind what makes or breaks it. When you consider the effort that goes into determining root causes and developing recommendations, why should it be such a hard sell to get something done?

With RCFA being a buzzword of the 90’s, companies are faced with a slew of new vendors with numerous RCFA methods and practices to help you attain quantum results. How do you decide who is going to make you money versus who is going to take your money?

There are many types of RCA tools available to organizations, including 5 Why?, Fault Tree Analysis, Interrelation Diagrams, Ishikawa Diagrams (Fishbone, Cause and Effect) and many others. A great example is the 5 Why? method: starting with the incident itself, an RCA team would continue asking “Why did this happen?” until they arrive at the root cause. Refer to the following example:

Hidden but powerful forces within our organizations are causing people to make serious mistakes. Until someone deals with these forces, they will continuously but unpredictably snare people into doing things they should not do. These forces are like a "trap," waiting to catch the next person. The most proactive of all industrial action might be to identify and remove these latent traps. But all our attempts to identify and remove these latent causes of failure start at the human. Humans do things "inappropriately," for "latent" reasons.

To successfully carry out this mission, a root-cause investigation needs to be evidence-driven in accordance with a rigorous application of the bedrock of all root-cause methodologies: the Scientific Method. Consistent with the Scientific Method, underlying assumptions have to be questioned and conclusions have to be consistent with the available evidence, as well as with proven scientific facts and principles. Sometimes root-cause investigations fail to fulfill their primary mission and the failure recurs. In that regard, diagnosing the root cause of root-cause investigation failures is, in itself, an interesting topic. Here are three common reasons why some root-cause investigations fail their mission.