Verification Versus Validation of Processes in Manufacturing Medical Devices

There are number of processes aligned one after another in the manufacturing flow chart of a medical device. However not all the processes are validated! Why? Let us get to the answer by understanding the terms Validation and Verification of Process.

Verification & Validation of Process both verify that the output of the process is achieved as per the defined specification. But what makes the difference here is when the output of the process can be subsequently monitored or measured it is called verification of process.

And if the output of the process cannot be verified by subsequent monitoring or measurement (here the out of Specifications or scarcity becomes apparent only after the product is in use) then that process is to be validated to prove that the process has the ability to achieve its defined output consistently.

Let’s clear the concept with an example of manufacturing process of Medical device (Metal implant):

Cutting of Metal sheet is a process used to cut the sheet to desired shape using Laser source. Here the desired output is dimensions of the cut sheet. These dimensions can be measured using the Vernier caliper or Calibrated Scale or if the dimension is too small they can be measured using Microscope with software for dimension measurement. Here this measurement of dimension against the desired specification is called Verification. That is, you are verifying the output against the desired specifications.

Similarly Annealing (Heat treatment process) is a process in which the properties of metal like tensile strength & flexibility are achieved by raising the temperature of the metal to extreme limit and then bringing the temperature down to a specific degree. Now how do we measure that the tensile property of the metal is achieved as per the defined specification? Here we need to perform destructive tensile testing i.e. in order to measure the tensile strength, the metal will be gripped from two ends and stretched until it breaks in two parts. So, if the manufacturer will check the tensile strength by breaking each and every medical device produced, what is he/she going to sell in the market?

Here comes the role of Process Validation!

Process Validation is a method in which Statistical Techniques/Procedures are used to prove that the process produces output as per the specifications consistently. Hence during the manufacturing process there is no need of performing destructive testing on each of the device manufactured.

Author: Supriya Kadam