Quality Control Tests for hardware
You might consider reading the ETSI EN 300 019 series of test specs.  While these tests specs were made for telecom, they provide a good list of the kinds of tests you may want to use to ensure the quality and reliability of electronics assemblies: 
• temperature
• humidity, 
• air pressure and speed
• insolation
• water ingress
• chemically active substances
• mechanically active substances
• mechanical vibration and shock
• flora and fauna
• etc.  
All defined in the specs.  Best of all the specs can be downloaded for free.

You can google "ETSI EN 300 019".  You can go to their website, https://www.etsi.org/.  But probably you want to start with a couple of specs to get you going.  

Example test spec:
https://www.etsi.org/deliver/etsi_i_ets/300001_300099/3000190103/01_60/ets_3000190103e01p.pdf

Overview:
https://www.etsi.org/deliver/etsi_i_ets/300001_300099/3000190100/01_60/ets_3000190100e01p.pdf


In terms of EMI/EMC testing, there is a good list at
https://en.wikipedia.org/wiki/List_of_common_EMC_test_standards

such as:

• IEC EN 61000-4-2, Electromagnetic compatibility (EMC)- Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test

• IEC EN 61000-4-3, Electromagnetic compatibility (EMC)- Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test

• IEC EN 61000-4-4, Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques - Electrical fast transient/burst immunity test

• IEC EN 61000-4-5, Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test

• IEC EN 61000-4-6, Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields


You can also perform reliability tests such as Accelerated Life Testing, Stress Testing.