Help me graph lab utilization
April 22, 2009 5:14 PM Subscribe
Please help me make more meaningful graphs for my boss! Our department runs computer labs on campus, and being the end of the school year we're looking at utilization rates. I can give him: number of users served per hour; number of machines used per hour; and average session time per hour. What he also wants is some sort of utilization, or fill factor graph. But none of us can really figure out what formula to use.
What do I mean by utilization/fill factor? Consider this example: Suppose a lab has 60 seats. Just by chance, 30 users come in sequentially, each using a different machine, for 2 minutes. That is:
* 00:00 - 00:02: user A uses machine01.
* 00:02 - 00:04: user B uses machine02.
* 00:04 - 00:06: user C uses machine03.
etc. Now, obviously the lab wasn't very utilized. But the graph will show we serviced 30 people in that hour, using 30 machines! We could have happily serviced all 30 people with one machine, however, the you can't see that from the graph.
That's a pathological case, but I think it illustrates what I mean. How do we measure this in a meaningful way? It seems to me that with the variables I have (login_count, login_average, host_count) I should be able to somehow derive a utilization but I'm stuck.
Note: I also have complete control over the data source and how these variables are built. So if I need to get a different number, or generate numbers a different way, please let me know!