8 Biggest Mistakes In Conducting Deviation Investigations-Part II

8 Biggest Mistakes in Conducting Deviation Nonconformance Investigations-Part II

This post, The 8 Biggest Mistakes In Conducting Deviation Nonconformance Investigations-Part II, discusses an additional 6 mistakes industry professionals need to avoid.

3. Not getting to root cause or most probable root cause

The percentage of investigations resulting in a root cause is a good metric for the health of the quality system. There are many reasons why root causes are not found. Not committing adequate time and resources is one. All too common, however, is putting in sufficient effort, having all the necessary facts and information, but still not being able to identify a root cause. This is sometimes due to the skill of the investigator involved, who may have been trained insufficiently, or does not have the technical command of the issues involved.

However, it is also surprisingly common for an investigation to conclude that “a definitive” root cause could not be identified, when all the information needed is available. A misguided interpretation of the facts, or using an unrealistic standard of “definitive” can prevent the investigation from arriving at a most probable root cause. There is no regulatory standard that requires all conclusions be “definitive.” A most probable root cause based on and justified by a thorough investigation, and review of available data and information is sufficient.

The proper root cause tool should be chosen for the problem at hand. For more difficult investigations, a Kepner-Tregoe or IS-IS NOT analysis can often tease out a challenging most probable root cause from an array of discordant facts. Using advanced root cause tools effectively takes experience and training.

There are many cases of organizations unable to realize and correct a root cause for a problem that was readily solvable and they suffered millions of dollars in losses or worse as a result.

4. Not getting to true root cause

A true root cause is the underlying reason that allowed the event to occur. Understanding the true root cause requires the collection of all relevant facts. Sometimes these are clearly understood moments after the event. Other times, it requires in-depth technical assessments and work that spans several months.

One good test for assessing if true root cause has been found is to see if the root cause needs to be stated in terms that are directly actionable, meaning it links clearly to a corrective action and is in the organization’s control. One of the simplest and most effective tests for assessing if true, actionable root cause has been found is use of the 5-Whys tool at the conclusion of an investigation, including application to outputs of a Fishbone or Kepner-Tregoe analysis.

Failure of the back-up power supply is not a true, actionable root cause. Why did the back-up power supply fail? Hurricane Mathew cannot be an actionable root cause, but an inadequate procedure for preventative maintenance of the back-up power supply is. The corrective action is to fix the procedure.

5. Unclear or difficult to follow investigation report

Many investigation writers forget that their audience is not just internal, but the ultimate audience is an external third-party, such as an inspector. Thus, the investigation needs to be readily understandable and clear with all the necessary supporting facts and rationale, even years after the event. The most difficult challenge in accomplishing this is writing logically and clearly and succinctly, without presenting redundant information.

6. Not assessing for contributing factors and associated CAPAs

Contributing factors are things that either were needed (in addition to the root cause) for an event to occur, or that increased its impact. Contributing factors also need root cause determinations and CAPAs. Addressing them limits the likelihood or impact of similar recurring future events.

7. Inadequate CAPAs

Too many investigations lead to an appropriate root cause, but are not linked to a CAPA. Most root causes and contributing factors should be associated with one or more CAPAs. If not, a clearly justified rationale should be given. Also, consideration should be given if an interim control is needed while the CAPAs are being implemented.

8. No interviews

Too many investigations fail to simply talk to the folks who have the most relevant insight and information surrounding the event. Memories fade quickly. Interviews should be conducted as soon as possible after an event. Some organizations “swarm” an event soon after it happens with a team and includes interviews. This is called “freezing the scene.” Gathering high-quality information soon after the event saves future time and effort, and improves the quality of the investigation.

Talking to key personnel with well thought out interview questions is also one of the most efficient ways to progress an investigation and should always be used when applicable. The essential details of such interviews should be summarized in the investigation.

In summary, good investigations are hard work, but the investment payback to organizations comes from improved operational performance, a reduction in costs, increased quality and improved compliance.

Note: To read Part I of this blog, please click here: 8 Biggest Mistakes in Conducting Deviation Investigations – Part I


This Post Has 2 Comments

  1. It’s worth noting that the Standards Boards are returning reports to Certification Boards which they consider contain NCRs closed and signed off by the CB’s client and the assessor with insufficient root cause analysis. I covered this in my article in the ASQ Six Sigma Forum magazine, “Your Opinion”. with special reference to the statement by the Boards that they would not accept root causes as being “operator, employee, human or anyone else’s error”.

    One of my aerospace contacts large companies even has a “Relentless Root Cause Analysis”.

    I can certainly think of other root causes to add to the above discussion.

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