I think you got the `900*9` wrong if you talk about experienced downtime. If you calculate discrete minutes (900*4,5+100*1)/1000 = 4,15 min (Unless you manage

I think you got the `900*9` wrong if you talk about experienced downtime. If you calculate discrete minutes (900*4,5+100*1)/1000 = 4,15 min (Unless you manage to inform the user since how long the website has been down already.) This could be made more accurate if we calculate it over seconds, which would drive the experienced downtime even lower!