I am trying to implement some real time monitoring. I have a real time data feed from which I can calculate the number of phone calls received in the last hour (now-60 minutes). I want to alert when this rate is more than 2 standard deviation from the mean rate. As some hours in the day will naturally have a higher rate than others I want to make this specific to the time of day.
Would the maths below achieve this or have I made any errors / is there a more appropriate way to handle data like this.
- 1) work out the number of calls per hour
- 2) find standard deviation for each hour
- 3) set threshold at mean for the hour plus two standard deviations
Thanks, Dan
Heres my sample table (this might not display very well!)
table,th,td { border:1px solid black; border-collapse:collapse; } th,td { padding:5px; }
Hour of day # Calls Received day 1 # Calls Received day 2 # Calls Received day 3 Mean Standard deviation Alert threshold 9 - 10 10 11 14 11.7 1.7 15.1 10 - 11 15 15 17 15.7 0.9 17.6 11 - 12 18 19 18 18.3 0.5 19.3 12 - 13 12 10 8 10.0 1.6 13.3 13 - 14 10 11 10 11.7 2.4 16.4