Hardware fails - it's a fact of life.
Every product has a predicted MTBF which can be obtained from your Cisco SE on request only because it's considered commercially confidential info and released under NDA.
There is some discussion of MTBF in general in https://www.ciscolive.com/c/dam/r/ciscolive/emea/docs/2020/pdf/R6BGArNQ/TECCRS-2001.pdf
If a product shows a trend of failing consistently more often than predicted MTBF then Cisco will start doing EFA (Engineering Failure Analysis) on RMA failed units to investigate root cause and identify possible design fault or inferior component quality, which will sometimes (but not always) result in a field notice being published - for example: https://www.cisco.com/c/en/us/support/web/memory-component.html#~tab-fieldnotices
If you want root cause the only option is to open a TAC case for every failure and if you can persuade TAC that the failure is higher than MTBF then they may agree with the BU to initiate EFA process. Be aware that EFA can take 3 months or more as it goes to a special engineering team for extensive testing and diagnostics and Cisco will only do it if there is a pattern of systemic failures above MTBF.
Of course you should consider obvious environmental causes like power surges, lightning strikes, operating in excessively high temperature conditions due to lack of cooling, humidity, dust/chemical pollutants etc which you are responsible for protecting against.
