WHY VALIDATE?
The simple answers: "It's the law." "The CGMPs require it."
The real answer: Yes it's the law, and the CGMPs require it. But let's look beyond such negative motivators.
Consider the real purpose of V&V. Not to satisfy a reg or audit,
tho that's what motivates many. The real purpose is to prove that whatever
you're verifying and validating (V&V) does what it's required to do, why it was acquired and
installed (requirements)? That requires that before you spend time on other
V&V activities, you verify (inspect, test, check, qualify) that it is
installed properly, i.e., all applicable manufacturer's requirements have been
met (electrical voltage, current, grounding, air exhaust, air treatment, safety,
environmental prep, and so on). If this isn't done first, then subsequent
V&V activities are compromised.
If some process or equipment may have been running for X years, and will be retroactively validated, it's safe to assume that it's installed properly. However, "assume" is not in the QMS (Quality Management System) vocabulary, so even with an established system, some checks must be performed (IQ), and all QMS' require documentation of that activity. You may do so and find some problems which will have to be addressed. Then you can progress with verifying and/or optimizing the settings used (DOE may be involved), whether you call it an OQ or not. Then you challenge the system repeatedly with all the extremes of allowable inputs (material, personnel, times of day, utilities fluctuations, etc) to show (whether you call it a PQ or not) that the system being V&V is robust and will virtually always deliver expected levels of quality with known and acceptable levels of variation (see recent drug process validation guidance from FDA), which will change / improve over time / lifecycle. These should be done, as needed, all or part, over the life time of the product / process / equipment involved.
If some process or equipment may have been running for X years, and will be retroactively validated, it's safe to assume that it's installed properly. However, "assume" is not in the QMS (Quality Management System) vocabulary, so even with an established system, some checks must be performed (IQ), and all QMS' require documentation of that activity. You may do so and find some problems which will have to be addressed. Then you can progress with verifying and/or optimizing the settings used (DOE may be involved), whether you call it an OQ or not. Then you challenge the system repeatedly with all the extremes of allowable inputs (material, personnel, times of day, utilities fluctuations, etc) to show (whether you call it a PQ or not) that the system being V&V is robust and will virtually always deliver expected levels of quality with known and acceptable levels of variation (see recent drug process validation guidance from FDA), which will change / improve over time / lifecycle. These should be done, as needed, all or part, over the life time of the product / process / equipment involved.
