To ensure high product quality and customer satisfaction, quality problems must be identified, analyzed, and resolved early. CAPA is a proven tool to help companies identify and eliminate the causes of quality deviations. It is a systematic process that enables corrective actions to address existing problems and preventive measures to prevent potential deviations.

This article aims to clarify the basic terms in the CAPA process, outline the steps of the process, introduce the 5 Why analysis as an effective tool for root cause analysis, and provide you with useful tips for a successful CAPA implementation.

1. Terminology

The following terms are frequently used in connection with CAPA:
Nonconformity, correction, corrective action and preventive action

To better understand and remember these terms, we can use a well-known but helpful example: a child falling into a well.

The Non-conformity In this case it would be that a child fell into a well.
The correction The immediate measure would be to rescue the child from the well and thus restore the original situation.
One Corrective action would be to fence in the well.
One Preventive measure would be to fence in all other wells as well.

This example provides an overview and simplifies understanding of the various terminology. In practice, a nonconformity means the failure to meet a requirement, while a correction is the action taken to eliminate the nonconformity. The goal of a corrective action is to eliminate the cause of a nonconformity or prevent its recurrence. A preventive action, on the other hand, is to eliminate the cause of a potential, but not yet occurred, nonconformity.

To eliminate the cause of a nonconformity, a systematic root cause analysis is required. The goal is not only to eliminate the nonconformity, but more importantly, to identify and address its cause. I will discuss a method for a systematic root cause analysis later.

2. CAPA process

The CAPA process consists of several steps:

1. Identifying quality issues: The first step is to identify nonconformities. This can be done through internal audits, customer feedback, or other quality control measures.
2. Root cause analysis: After identifying the problems, it is important to determine the underlying causes. This requires a thorough analysis aimed at identifying the root cause(s) of the nonconformity and addressing them specifically.
3. Corrective action planning: Based on the results of the root cause analysis, corrective actions are planned. These actions are intended to eliminate the identified causes and resolve the nonconformity.
4. Implementation of corrective actions: The developed actions are implemented to implement the planned improvements and resolve problems. This may include, for example, training, process changes, or repairs.
5. Verify effectiveness: After implementing measures, it is important to verify their effectiveness. This can be done through monitoring, re-auditing, or retesting to ensure that the problem has indeed been resolved and the desired results have been achieved.

The CAPA process also includes the development of preventive measures. These measures are intended to address the root causes and improve processes, procedures, or training to prevent the recurrence of these problems.

3. The 5 Why Analysis

The 5 Whys analysis is a simple yet effective method for root cause analysis of nonconformities. To find the root cause of a problem, you repeatedly ask "why?" questions until you get from the obvious cause to the underlying causes.

The procedure is as follows:

1. Identify the problem → clearly define the nonconformity to be analyzed
2. First Why Question → Look for the most obvious cause of the problem
3. Next Why question → based on the answer to the first Why question to identify the root cause that caused the previous problem
4. And so on → Ask further questions (guideline 5 questions) until the underlying cause is reached. Carefully analyze the last answer, as this is ideally the cause of the nonconformity.

It is important to proceed objectively and in depth, to avoid hasty assumptions and to find as precise, specific answers as possible to each why question.
There's no upper or lower limit of five questions. The number can vary depending on the complexity of the topic. It's important to delve sufficiently deeply, but also not to go into too much detail and to stop at the right point.

4. Learnings

• Often, the root cause of nonconformity is, to put it bluntly, "human error." However, this isn't a big deal and is easily remedied, as everyone makes mistakes, and the basic idea of CAPA isn't to punish, but to find a way to prevent recurring errors.
• As a corrective measure for "human error," training on this topic is usually the best way to address it. This allows you to address and discuss any ambiguities in detail.