If you created some application with the arduino boards or using AVR or PIC chips, how good is their long term reliability and robustness?
For example, PLCs are engineered specially to take a beating, long continuous cycle times, electrical circuit protection, and good mechanical protection against shock etc. So ultimately PLCs tend to be workhorses and great for automation applications because they are reliable for long term continuous use and are very robust.
Are arduino boards and AVR and PIC chips as good in terms of long term continuous operation? How reliable are they? Provided of course you are supplying power constantly and it wont be in a situation where it will get knocked around. For example, will the internal circuit inside the microcontroller or on the PCB reach end-of-life or premature failure after being cycled for a long time? What does your experience tell you? How long can you run them continuously before you get 'bugs' or hickups or even total failure?