Musings: MTBF and MTTR

[+rragan]

I got to wondering if Mean Time Between Failures and Mean Time To Repair would be interesting metrics for a cache owner. So would a higher MTBF value suggest better designed, more robust caches? Would a lower MTTR suggest better attention to prompt fixing of Needs owner attention? I suspect a larger number of caches that an owner has would offer a more stable measure over time.  These seem like things that would be on the owner dashboard and which some owners might strive to improve. I'm guessing this idea will likely die but might trigger some discussion. It's very half-baked as to how it would be implemted to provide a useful measure. 

[+barefootjeff]

58 minutes ago, rragan said:

I got to wondering if Mean Time Between Failures and Mean Time To Repair would be interesting metrics for a cache owner. So would a higher MTBF value suggest better designed, more robust caches? Would a lower MTTR suggest better attention to prompt fixing of Needs owner attention? I suspect a larger number of caches that an owner has would offer a more stable measure over time.  These seem like things that would be on the owner dashboard and which some owners might strive to improve. I'm guessing this idea will likely die but might trigger some discussion. It's very half-baked as to how it would be implemted to provide a useful measure. 

 

Hmm, I think I'd score pretty badly on that as, of the 49 active physical caches I've placed (excluding the three I adopted), only about a dozen have ever needed repair and most of the time that was early in the life of the cache when something caught me by surprise, like what appeared to be a snug dry hiding place under a ledge turning into an underground watercourse in heavy rain. When there has been a problem like that, I've replaced the container with something that will cope better and most of the time there hasn't been another failure. The rest, some dating back over a decade, are still the original container with its original logbook, although I've occasionally logged an OM when checking on them after a deluge, fire or DNF just to confirm the cache is fine. As for MTTR, I've never received an NM/OAR log so I don't know what that would be calculated as.