You leave this wide open! What type of reliability are you interested in? Parts? Mfg. QC? Maintenance & service? To name some areas of concern. Google MTBF (mean time before failure) to get a start. A lot of lengthy books on this subject are available! E
My electrical utility company gave away compact fluorescent light bulbs for free. But some of them dripped melted plastic that was ON FIRE!
All the bulbs were recalled and replaced.
The Chinese manufacturer copied the certification label from a competitor so the product was not designed to be safe and was never checked properly to be safe.
If you want a reliable product then buy from a Name-Brand manufacturer.
Use the "best" (and perhaps most expensive) parts available and use a circuit design that imposes the least stress to all the components.
More than that, consider redunancy in your equipment.
But be aware that this would NOT be the best engineering approach because it will not be the best trade-off between all technical/economical aspects that matter.