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How To Write An Effective Deviation That Gets To The True Root Cause

How to Write an Effective Deviation that Gets to the True Root Cause

What is a Deviation?

A deviation should not be viewed as your “worst nightmare”. Instead, a deviation should be seen as a way to root out inefficiencies in your biopharmaceutical manufacturing process.

A deviation is a departure from the norm that can be traced back to a predetermined set of standards and conditions, known as acceptance criteria.

How to Investigate a Deviation

Once a deviation has been identified, you should begin the investigation into its root cause right away. It’s important to have conversations with the people closest to the deviation within 24 – 48 hours while their memories are still fresh. The conversations should ultimately answer the “Who, What, When, Where, and How” of the deviation.

Who (which department) discovered the deviation (names, roles, shifts)?

What was happening leading up to the deviation (processing, cleaning)?

When did the event(s) occur (dates, times)?

Where did the event occur (building, floor, process area)?

How was the deviation first discovered? What changed?

Framing the investigation as conversations and not as interrogations is important to guard against people getting defensive. You want everyone to be truthful and forthcoming about the deviation, as well as any relevant events that led up to the deviation. Their insights, being so close to the deviation, will be valuable when drafting the deviation report.

This takes us to the next hurdle in finding the true root cause – bringing it all together into a deviation report.

What is the Purpose of a Deviation Report?

Every operating facility is different and may name certain sections differently. However, the purpose of a deviation report remains the same: To determine the impact on quality.

What are the Key Sections of a Deviation Report?

There are 6 key sections of a deviation report:

  1. Title
  2. Executive Summary
  3. Description
  4. History of Trends
  5. Root Cause
  6. CAPAs (Corrective Actions and Preventive Actions)


The title of a good deviation report clearly identifies the acceptance criteria that were not met as well as where the deviation occurred. Provide sufficient detail in the title such that it’s easy to search in the future.

Executive Summary

The executive summary should be one page – no more.

To keep the Executive Summary to one page, it’s useful to break it up into 4 main paragraphs that cover the following topics:

  • What happened
  • Impact to Quality
  • Immediate remedial actions
  • CAPAs assigned


The results of the conversations that you had with the people closest to the deviation go here. The “Who, What, When, Where, and How” should be clearly identified in this section. Think of it as telling the story of the deviation.

Be sure to include only relevant information that directly ties back to the deviation. As you get further into the investigation, it will become apparent which information to keep, and which may no longer be relevant. However, at this early stage, just take everything down. It’s easier to weed too much information out at the end than to not have enough to begin with.

History of Trends

It’s important to do some digging to determine if this is the first time this deviation has occurred. A repeat deviation should raise an immediate red flag that any remedial actions and CAPAs implemented the last time were not effective. A deeper dive will be necessary the second time around.

Root Cause

Many tools are available to sift through all of the information that is generated from a deviation, including fishbones and 5 Whys. Sometimes the most trivial thing ends up being the root cause. Therefore, you should go through each event and factor thoroughly to determine the impact to the deviation.

Hint: You know you’ve got to the root cause such that if it were removed, the deviation would not have happened in the first place.

CAPAs – Corrective Actions | Preventive Actions

Corrective Actions are the immediate responses to the deviation to bring the process back into a state of control. For example, if a leak was observed in the production area, closing or isolating the valve further upstream would be an example of a corrective action.

Preventive Actions, on the other hand, address the underlying cause of the deviation. Going along with the example of the leak just described, does this valve need to be replaced altogether? Has this valve reached its end of life? Are the valve internals compatible with the operating conditions of the process it’s in? These are the types of questions that drive preventive actions.

Just setting up the CAPAs is half the battle. Implementing them is just as important. Set up an effectiveness check at a set time following the implementation of a CAPA to determine if the CAPA is working as intended.

Getting to the True Root Cause

Starting the conversations early and being thorough with your investigation is key. In this way, you’ll be able to close deviations in a timely manner and ultimately arrive at the true root cause.

This article was originally posted on the BioBuzz website.

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