Previously, you have determined when validation is necessary in your organization and what validations to perform. For other details on this, please see previous posts:

https://streamliningvalidation.com/2019/12/04/when-to-perform-which-validation/

https://streamliningvalidation.com/2019/08/05/sample-post-1/

As your organization moves into ongoing production and design changes, you need to determine when the validations are no longer valid and need to be performed again. Also, you will need to determine how much of the validation needs to be performed after the initial validation has been completed. Is it the entire validation being repeated, or just a subset? You need to identify what are the drivers that require validation to be performed after the initial validation. You will need to determine when to perform the revalidation, how much validation to perform, and how to document this information. 

The first step is to determine when to perform re-validation. There are many drivers that could cause a company to need to perform validations after the initial validation. One of the first questions that you should ask is what in the validation has become invalidated and would need to be challenged again or what has changed that hasn’t been previously challenged in the previous validation. Keep in mind that the validation is not just to look to see what could be affected, but to prove what isn’t affected. Below are some situations that would need evaluation to determine if re-validation is necessary.

             The first situation that could cause a validation to be invalidated is if the equipment that was validated through an installation qualification (IQ) is moved. Depending on how far the equipment was moved, how the equipment was packaged between moves, the technical elements of the equipment that could have been altered by the move, and the utility hookups that are different and need to be challenged, the equipment may need to be re-validated. 

             A second situation that would cause a validation to be invalidated is when a new process window is determined to be needed for a process. 

If the new parameter window is within the old process window, then the new process window has already been challenged and would not require a new validation. For example if the old process window was 150 to 200 seconds and the new process window is 180 to 190 seconds. 

If the new process window has some crossover of the old process window, but there are parts of the process window outside of the old process window, then the areas of the process window would need to be re-validated. For example if the old process window was 150 to 200 seconds and the new process window is 180 to 230 seconds. 

If the new process window and old process window are unique, then the new process window would need to be validated. For example, if the old process window was 150 to 200 seconds and the new process window is 230 to 280 seconds. 

             A third situation that could cause you to need to revalidate is if the product failure rates increase or product complaints have a new or increased failure rate. Before jumping into validation, first complete a failure investigation to find the cause of the failure. Otherwise, you would be just confirming the process as is. If the failure investigation finds the cause of the failures to be equipment, setting, process, or operator instructions related, changes may be needed to production. Once those changes are put in place, you should evaluate what needs to be validated based on what changed and what other parts of the process may have been affected. 

             A fourth situation where you would need to evaluate the need to revalidate is a change in processes or a design change. Besides the failure investigation as listed above, there could be other drivers to cause a design or process change such as cost cutting measures, end of life for a component, or a technology change. These would follow the same evaluation discussed in the previous paragraph. 

             A fifth situation where you would need to evaluate the need to revalidate is a change in equipment. This could include a different piece of equipment being added to the process. An example of that is taking a previously manual process and automating it. This could include changing one piece of equipment for a different kind of equipment. An example is changing out one technology for another. This could also include changing out one piece of equipment for a like replacement or major repair. 

Once you have determined what needs to be re-validated, the second step is to determine how much validation to perform. A good place to start is evaluate what from the previous validation is no longer valid or what was not covered in the previous validation. Again, keep in mind not just what directly is changed, but also what could have been affected by the change. Below are several examples of what level of re-validation might be needed. 

              The first example is increasing or moving parameters (as described above). In that case, you would challenge the aspects that were not previously challenged. This could be where the process parameters are overlapping the previously validated parameters and would need to only validate the new parts of the process window. Or this could be a complete re-validation if the parameters are completely different than previously validated. 

               The second example is moving equipment. You would need to evaluate what could have been altered and affected by moving the equipment. Evaluate how far the equipment was moved. Evaluate how the equipment was packaged for the move. Once you have a good idea of what aspects of the equipment were at risk of being altered or could alter the outcome of the process, then you can plan for challenging those elements in the re-validation. 

               The third example is changing the  processes or equipment. Depending on what has changed and how this potentially affects the processes around it, the level of re-validation could be a subset to re-validating the entire process. 

                 The fourth example is an increased rate in failures or complaints. Based on the cause of the issues and what fixes are put in place, then determine what part of the original validation is invalidated or was not previously covered in the validation. In this case, you may need to do entire validation again.

Provided above are many examples. These are not all the potential situations that could come up. The specifics could change the decisions as recommended above. It is important to determine what technical justifications there are for performing or not performing validations, what level of validation is needed, and what assumptions are made in those decisions. It is important to document those decisions, assumptions, and rationale as a part of the validation to ensure the record is complete and is a stand-alone document. 

Once you have a good baseline on the validations, it is important for your company to build a re-validation process as well. Many things happen over the life of a product, both by choice and from things outside of your control. It is important to have a process to understand when your process is no longer in control and needs to be checked again through validation. It is also important for your company to have a process of validation in the case of change. A complete validation process will allow your company to have and maintain a robust production process.