How Do You Define Reliability?

How do you define reliability?

A Koch Machine Tool Service Tech recently did a preventative maintenance on several FANUC RoboDrills at a customer's shop. He was amazed, of the half dozen FANUC RoboDrills, the number of tool changes was 18,000,000 - 22,000,000, and still running!

For my simple mind, I have a hard time wrapping my mind around a number like this. I decided to try to break this down. The FANUC RoboDrill has an automatic tool change time of just under a second - tool to tool change time. 18,000,000 tool changes equals about 18,000,000 seconds which equals 300,000 minutes or 5,000 hours. One shift is about 2,000 hours per year.

Another machine had over 22,000,000 tool changes...that is over 3 years of continuous tool changing!

Another reason why FANUC RoboDrills fit the mold for an automation cell.