Product and Process Validation


Product and Process Validation – When to validate:

i) The sensitivity of routine end testing to determine the safety, compliance and efficacy of the finished product, will influence when to validate.

ii) Where clinical or destructive testing would be required to show that a manufacturing process has produced the desired result or product.

iii) When routine end-product tests do not reveal all variations in safety and efficacy that may occur in finished products.

iv) If the process capability is unknown, or it is suspected that the process is barely capable of meeting the product specifications then validation needs to be performed to determine if the process is suitable to manufacture the product.

v) Validation can be seen as part of on-going quality improvement. Therefore even where inspection and testing can confirm conformance to requirements, validation may be performed in order to gather data as part of continuous improvement efforts.

vi) Validation may also be seen as an opportunity to improve operating efficiency. Where validation demonstrates a consistent, highly capably, highly reliable process, then subsequent inspection and testing may be reduced with consequent cost and process lead-time savings.

vii) Where process results cannot be fully verified during routine production by inspection and test, the process should be validated according to established procedures.

Types of Product and Process Validation.

There are four categories of Validation based on the approach taken, namely:

Prospective Validation.
Where the validation is pre-planned in advance.

Concurrent Validation.
The validation is based on data collected during actual performance of a process already in place.

Retrospective Validation. 
Where a process is already in operation, but has not been validated according to a prospective protocol and concurrent validation is not a realistic option.

The implementation of a program of repeat validations based on time or due to changes in the operating environment.


Prospective validation.

Prior to a process being approved to manufacture a product, the process is validated to confirm that it can operate as intended. The validation is planned out, validation protocols are approved, acceptance criteria are agreed in advance of the process being “signed-off”. This is the most common approach to validation. It is normally applied when a new facility, new production line, new products and new product redesigns are planned for release. In larger organizations where research and development may take place in one location and manufacturing in another location, prospective validation will normally be planned and implemented to confirm that the product as designed by research and development is repeatedly manufacturable to design and customer needs.


Concurrent validation.

With a process in ongoing operation, validation can be performed to confirm that the process is operating in a controlled manner. In non critical processes, this approach can allow faster implementation of process changes, without compromising the customer. This approach is also suited to well established manufacturing processes where there is a high level of confidence in the stability of the process and hence the quality of the outputted product.


Retrospective validation.

Where prospective or concurrent validations have not been performed on a process which requires validation, then a retrospective validation will need to be performed. A retrospective validation will make use of historical data, test and measurement results, analytical analysis, etc., to confirm that the process operated as intended. In many instances it will not be possible to test to the design limits, therefore this form on validation will consequently be of more limited value.

Retrospective validation implies that the process has been in use with product shipped to customers in advance of validation sign-off, therefore this form of validation is not generally accepted by regulatory bodies.

Retrospective validation however, has a role in facilitating process audits, where there may be a independent program of checking the validity and integrity of on-going prospective and concurrent validations.



In all validation programs the requirement to recheck process performance needs to be considered. A process may be capable when initially established, all equipment will be new, employees may be trained on the most up to date practices, there may be significant management focus on adherence for procedure. However, over time, unless tight controls are maintained, the equipment may begin to deviate from specification center due to wear and tear, employees may become focused on production targets versus quality, management may be focused on cost reduction. Therefore, it will normally be necessary to perform full are partial repeat validations on a regular planned basis.

In addition whenever significant change arises or is planned, revalidations will need to be considered, for example:


New product introductions into existing processes.

The introduction of new suppliers.

Changes in raw materials or material mixes.

High staff turnover.

Changing patterns detected in yields.

Customer complaints or product returns.

Product and Process Validation Full Details

Product and Process Validation.