HAST, HALT of the single component (not the entire product)

[Oleander]

Hello,

I am facing now a subject/problem that can be described as reliability testing of the new components that are to replace its harder-to-buy (stock emptied, price too high) equivalents.
Final products are mainly off-line power supplies. Components considered are ICs, opto-couplers, mosfets, some controllers too.
As HAST, HALT testing is targeted to entire product pieces, such results may lead to an excessive amount of data, not necessary related to the exact component actually changed in a PCB for testing.

Where can I find more information about such testing, case studies, traps, unexpected failures ?