How do I estimate the lifespan of a microcontroller?

Hello everyone, I have some concerns bothering me.I would like to know how one can estimate the lifespan of a microcontroller (for example AVR).
And can microcontrollers work 24/7 ??

Solution

Microcontroller lifespan estimation depends on operational and environmental conditions. Properly designed microcontrollers can work 24/7 with adequate power management and cooling.