MTBF predict

[thomastong]

My company wants to predict product's MTBF. Can I only perform 3 tests as below setting to get it?
Thermal cycling (TC) (-40 to 85oC, 30mins/cycle, 3000cycles or 50% failure whichever comes first)
Temp-Humidity ALT Product storage life test 85C/85%RH, 1000hrs or 50% failure whichever comes first

High Temp Operating Life (HTOL) Product life Power-on at 50degC for 1000 hours for pass/failure, 3000 hours or 50%failure whichever comes first

[tarik]

A good test would be one that tests many units and under many levels of whatever stress type you have. Do you intend to test every unit under all these conditions? Are all the stresses applied simultaneously or does every unit go through these test sequentially (in phases)? Or do you test different units under different conditions? Also note that MTBF is not a great measure of reliability. It's usually an overused metric that could result in misleading conclusions. I recommend assessing reliability at a certain time with certain confidence level.