How should I measure Concurrent Licence Usage

Question

Hi

I have detailed stats on user access to my system detailing login and logout times as well as machine used, network username etc.

I am in need of measuring what I would term a concurrent user licences level based on this information. Now I could take the maximum logged in for any 1 day in a 3 month period say 170 or I could take the average say 133.

Does anyone have or know of a formula for working this out or is it as simple as the high water mark which is 170 in my example.

A client has recently gone from an unlimited licence to a concurrent licence so I am faced with the task of setting the initial licence level. There is potential for more licence sales in the future so I don't want it set to high and I do want it based on historical data that the system collects rather than guess work.

Answer 1

I'd take a % of the standard deviation from mean. I.e. if your mean is 133, then work out the standard devitation then go for 70% of that on top, maybe 80%. That way you ignore the outliers and get a good indication of the real number you need.