My thought was the fail probability was more like 10 (-9). Oh well, at some point, it was 1/1.
You can calculate anything you want against failure probability, years of total jet fleet operations since 1956 to present or just time on the wing for this specific engine.
The design intent was zero and as such the future expectation must be brought back into compliance under Continued Airworthiness regulation.
The so called 10 (-9) numbers only apply to combinations of aircraft systems and specfically exclude any system like engines which have their own standards e.g. Part 33 regs