Design Flaws noted after FAT

How does one handle the following problem…Completed 2 FATs at 2 seperate suppliers successfully,(more of a component check as the 2 units are 12 000km apart) installed the equipment, (chiller unit and AHU.) Start up no problem but
1-AHU could not attain the design temperature and humidity levels. It was discovered that the calculated heat load for the area was insufficient so extra heating was installed.
2-Chiller unit kept shuting down. The supplier made 7 changes over a period of 3 weeks to their standard set-up (including change of hardware) to prevent this from occuring.

It now seems that the systems are “behaving”.
How would one handle these changes to the design specs. Drawings need to be altered, etc
As for the documentation part!!! the Commissioning/IQ/OQ protocols have already been approved for use as per the design specs and the commissioning docs are 3/4 executed when this was noted.

Change Control? Deviations? How? The design has been altered already!
HOpe someone can be of assistance.



Hello Waynem,

First of all I would have completed the FAT and IQ/OQ’s etc to completion and when any problem occured I would have raised a deviation/obervation to deal with these issues.

Once complete I would then create a change control detailing how exactly you plan to fix these problems.

For example test 7.2.36 failed due to an error in the design document.
Resolution is to amend the design document and update the FAT, IQ/OQ to reflect these changes. Be specific as to what exactly you are updating and where in each document. Detail in your change control how you plan to re-execute. For example do you need to re-execute the entire validation or are you happy just to partially validated the affected sections. Perhaps some kind of Risk assessment needs to be performed to justify this approach.

Hope this helps

Hi gokeeffe. I was hoping to Close-out version 1 of the IQ/OQ with all the “obsolete” drawings etc and point it in the direction of a single change control. The change control would clearly stipulate the findings and the corrective measures, which would be to create Version 2 with the new design criteria.
One decent change control instead of many deviations or change controls which would then make the qualification package look untidy.


Also having come through many FAT with such upsets like you describe, what I do is the following; complete out the FAT protocol as fully as I can. Open 1 deviation on site and get resolution while on site.
If documentation needs to be updated this can be done then prior to SAT.
I have never had my IQ/OQ approved prior to FAT as its not reasonable to do so and expect everything to work perfectly. The FAT should challenge your system and it gives you the freedom to make changes if necessary. Once everything gets documented there should be no problem with a regard to control of the situation.
You need to state in your deviation the exact changes include all updated drawings etc. I agree that too many deviations cause the package to look tidy but in saying that one overall deviation can itself look untidy if too much information is packed into it.


Thanks Ruth Cunniffe and gokeeffe, it is always great to get the perspective of others. Helps to align the mind. :slight_smile: