Case Study: Root Cause on Seal Failure in Refinery

What we need to do today is make management aware through education and awareness that our cultures live with these chronic events that typically end up costing 100 times more than the occasional sporadic event. Unfortunately, the sporadic events get all the attention. When our cultures are enlightened, we will begin to enjoy the fruits of our efforts in the form of return on investment (ROI) figures as high as 7000-8000 percent. Then the believers will come.

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:

I was recently engaged by a client to conduct failure analysis on a large (and expensive) hydraulic cylinder off an excavator. This hydraulic cylinder had been changed-out due to leaking rod seals after achieving only half of its expected service life. Inspection revealed that apart from the rod seals, which had failed as a result of the 'diesel effect', the other parts of the hydraulic cylinder were in serviceable condition.

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.

The business process is most commonly named Root Cause Failure Analysis (RCFA) or root cause analysis. The name itself implies the largest and most expensive problem when implementing problem solving in an organization. The results wanted from the process are to eliminate the problem, not to analyze the failure. To convey the desired result to the organization, the name should therefore be changed to Root Cause Problem Elimination (RCPE).   

Lately, I’ve been asked to provide root-cause analysis training more than ever before in my 14 years as an independent quality/lean consultant. This is interesting in the age of Six Sigma, especially because “analyze” is the heart of DMAIC (define, measure, analyze, improve, control). I find this interesting in this age of lean, in which the lean tools that are taught to so many people are only possible solutions to good root-cause analysis. I began to wonder, “Why does root-cause analysis suck?,” and I came up with the following possible root causes. You decide which apply to your company by asking “Why?” somewhere around five times until you find the systemic reason(s) that it sucks at your company. Drum roll, please . . .