I've worked with threshold logic like that for collecting and analyzing traffic on telephone switches where an alarm or notification would be generated if the t

I've worked with threshold logic like that for collecting and analyzing traffic on telephone switches where an alarm or notification would be generated if the threshold was broken. Personally I would never want to debug something like that using a statistical probability that something might have gone wrong. Better to fail gracefully with something like multiple chains so that when a request chain goes down it gets logged, cleaned up, and recreated. Worst case scenario they get a request timeout warning.