Abstract: If we reflect twenty plus years ago, we will recall that most of our quality efforts were directed checking the quality of the final product in the finishing and packaging stages.  By that point, if something was found defective, we would have to scrap the entire run or lot of products produced.  Then came the TPM initiatives that stressed “quality of process” and we started to implement Statistical Process Controls (SPC) and Statistical Quality Control (SQC).  We started to look at quality “during” the manufacturing process ensuring that when the finished product came off the line, it was a quality product.  Can we do the same with Root Cause Analysis (RCA)?

Taking the TPM parallel described in the abstract above, let’s see if it applies to non-manufacturing processes such as RCA.  If asked, almost everyone will say they are doing Root Cause Analysis (RCA).  And to a large part, they will be correct in their own minds.  This is because of how they define RCA versus how the person asking the question defines RCA.  This is like if we asked a sample population, “Do you live a healthy life?”  The majority would reply with an emphatic YES.  However, what does healthy mean to these people?  To some if means we are alive, to others it means that we eat right and exercise, to others it means that they are emotionally sound and to others it may mean that they are content in their religious beliefs.

So how many ways cannot someone interpret RCA?  Some believe it is 1) having the local expert provide us a solution, some believe it is 2) brainstorming in a room and drawing conclusions from hearsay and some believe in 3) the use of a disciplined thought process to seek true root causes. 

1)      When the perceived expert provides a solution as an individual, we are more apt trust their instincts, spend the money and their solution and see if it works.  Sometimes it works, but more often that not, it does not work.  Checking to see if the solution works is like checking quality only at the finished product stage.  It is too late if there is a defect found!

2)      When teams are used to brainstorm using quality techniques such as fishbone and/or 5 WHYS, they will usually draw conclusions based on majority opinion.  This means that solutions tend to be implemented based on the consensus of the group’s opinions, not on any factual basis where tests prove that these opinions are correct.  Again, we are checking quality of the final product and not of the thought process that drew the conclusions.

3)      When teams use a disciplined RCA process that requires hypotheses to be developed as to how something could occur, and then REQUIRE verification with some essence of science as to whether it is true or not, then we are employing quality of process!  This is because we are proving our hypotheses with facts rather than relying on hearsay, assumptions and ignorance.

To demonstrate these points, look at the following abbreviated example: 

Figure 1.0 - PROACT^® RCA Disciplined Logic Tree

  The above depicts a disciplined thought process called PROACT^®.  Let’s think back to our RCA scenarios.  If a critical pump were to fail, in some cases we would get our best engineers to take a look at it.  They would do their engineering magic themselves and may conclude that a different type of bearing (perhaps more heavy duty) should be in this service.  We would change out the bearings with the new designed ones.  Given the above scenario, would the problem go away?