QMI Brief Newsletter

10/24/2006
Root Cause Analysis and Effective Corrective Action

Countless articles and papers have been written about Root Cause Analysis (RCA) and performing effective corrective action due to the fact that there are many organizations that require help doing both. The following paper will examine how doing a good job of RCA will lead to effective and lasting corrective actions.

The need for corrective action can arise from many different sources including internal audits, external audits, customer complaints, employee complaints, injury reports and the requirements of regulatory bodies. The aforementioned audits may include Quality Management Systems (QMS), Environmental Management Systems (EMS), Occupational Health and Safety (OHS), or any number of other requirements-based systems. The point is that all of these inputs to the corrective action process should be dealt with in a timely and effective manner.

So what do we mean by effective corrective action? The ultimate goal of performing corrective action is to eliminate the actual cause of the problem. If an action, or a series of actions, is implemented and eliminates the actual cause of the problem, thereby eliminating the possibility of recurrence, then that would satisfy the criteria for effective corrective action. All too often the people responsible for providing corrective action responses focus on the incident itself, rather than the larger issue of what caused the incident to happen.

The first step in getting to an effective corrective action solution is to clearly understand what the problem is (or is not). Sometimes the statement of the problem (hereafter referred to as a nonconformity) can be so vague or poorly stated, that it will quickly lose its meaning and perhaps lead to no meaningful action at all. A QMS example of this would be “Documents are not always controlled.” What documents? Where did you find these documents? Why do they need to be controlled? This type of nonconformity statement will not result in any useful type of action being taken to correct the problem.

A properly formatted nonconformity statement will include the statement of the nonconformity, the actual requirement that was not met and the objective evidence that was observed. In stating the nonconformity, it is most useful to state the problem as a problem with the system. This will take the emphasis off of the incident, and begins to focus on the cause. As mentioned before, the requirements that were not met can be related to QMS, EMS, OHSMS, or any other requirement imposed on the organization, and a reference to the requirement will ensure that the focus is to become compliant. The objective evidence will provide the respondent with an actual incident to investigate while performing RCA.

The following example is a nonconformity raised against a particular clause of the QMS standard ISO 9001: 2000.

9001_5_whys

At first glance, without doing any RCA, the immediate action would be to provide the Work Center with the most current version of the document to satisfy the requirement. This would be considered “containment” action, and should definitely be done as part of the corrective action process. But, without finding out why this happened in the first place, the problem is likely to be repeated when the SOP goes through its next revision. By addressing the nonconformity at the system (or process) level, the corrective action team is forced to investigate further to determine how widespread the problem is and then address the larger contributing factors to the problem. This is where good RCA is vital.

There are many types of RCA tools available to organizations, including 5 Why?, Fault Tree Analysis (FTA), Interrelation Diagrams, Ishikawa Diagrams (Fishbone, Cause and Effect) and many others. Perhaps one of the easiest to implement is the 5 Why? Method. Starting with the incident, a corrective action team should keep asking “Why did this happen?” until they arrive at the root cause. Refer to the following example for clarification.

9001_sample_non_conformance
As you can see, the corrective action team has drilled down to some underlying issues that allowed the system to fail. Now we have some good candidates for corrective actions to be taken. In this case the problem was not the document control system itself, but another process that acts as an input to document control and distribution. Taking action on the actual cause of the problem will likely eliminate the possibility of this problem recurring.

But how can a corrective action to the problem be verified for effectiveness? Considering the problem in our example would likely be the result of an internal or external audit observation, it would make sense to use an audit for verification purposes. In some situations it might take a period of months to pass before an audit would be suitable to evaluate the effectiveness of the actions taken. If the problem has not recurred since the implementation of the corrective actions, then we can assume that the root cause has been correctly identified and eliminated. If there are similar problems found on verification audits, then there would be a need to revisit the RCA process and initiate new corrective actions based on the results.

A common problem with RCA during the corrective action process is that many organizations will stop at “Operator Error” if that is one of the causes of a given problem. While in many cases the human factor may well have contributed to the incident, there is likely a system the failed, or was not in place, to avoid the problem. “Operator Error” root causes usually result in a brief meeting with the subject operator to remind him about how to do the job. While this might work for some people for some of the time, it is not likely to result in any sort of lasting protection from recurrence.

For example, an operator is producing left-hand and right-hand widgets on the same piece of equipment. The left-hands and right-hand widgets are to be placed in different shipping bins. The potential exists for the operator to mix parts, as there is no system to prevent it. In the event of a customer complaint about mixed parts, it is likely that the cause of the nonconformity would focus on “Operator Error,” leading to ineffective corrective actions that do not prevent recurrence. This situation lends itself to potential customer dissatisfaction and repeat problems with the same parts. This risk to the customer may be high and the cost of containment (on-site sorting, 100% or 200% inspection) would definitely make a strong argument for investing in some good RCA and effective corrective actions.

Using this same example, 5 Why? RCA might uncover that the Production Planning Group failed to implement any sort of mistake-proofing to prevent mixed parts. A system for mistake-proofing the operator’s process could probably be developed and implemented in timely and cost-effective manner, thereby eliminating the root cause and providing the operator with tools to perform the job correctly. Auditing of the planning and production processes after implementation will determine the overall effectiveness of the corrective actions taken. Is the mistake-proofing installed? Is the operator using the mistake-proofing equipment correctly? Has subsequent inspection revealed any escapes? Have customers had repeat complaints about mixed parts? Are mistake-proofing concepts being applied to similar processes?

The end result of utilizing sound root cause analysis practices should be effective corrective action. The end result of effective corrective action should be improved processes, and ultimately improved customer satisfaction. Regardless of the nonconformity’s source, organizations that only take action on the incidents are bound to repeat the same ineffective corrective actions over and over again. The purpose of this paper was to present you with a common sense approach to implementing RCA and effective corrective action. All organizations will experience different problems with varying degrees of severity. But, by applying some good investigative tools and taking appropriate action of the causes of problems, repeat issues can become a thing of the past.

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