Aircraft undergo extensive testing during their development, but it’s not impossible that a previously unforeseen problem will develop following production. The systems installed on aircraft are primarily there to help fly the aircraft and not to gather data in a manner conducive to identifying aircraft issues or performance.
The solution is to install systems similar to what was used during the flight test campaign, right? Unfortunately, this can be an expensive prospect as it usually requires installing a large amount of additional cabling and avionics. This makes sense during a flight test campaign when you need to spend a protracted period of time gathering extensive data, but not when you just need to troubleshoot a specific problem. Installing such a system also takes a lot of time and can be costly due to the delays introduced before data can be gathered.
PTIE should be able to gather data from different systems and sensors, and store such in one location