CAPS = BHCA/3600
BHCA=Load*3600/MHT
MHT= Mean Holding Time = AHT = Average Holding Time = TMO (Tiempo Medio de Ocupación)
Load=channels * traffic per user
channels = channels or users (depending on what you want to calculate)
traffic per user = number of calls a user usually makes (or number of times a channel is seized, depending on what you want to calculate) in one hour
Finally, you will be able to find the concept of BHCC, which in the industry we calculate as:
BHCA = BHCC * 3
Where 3 is an estimated figure of the number of attempts a user (or channel) usually try when making a call. This figure can be adjusted per your convenience, depending on what you are designing.
I hope this helps
Simon (Evolutio)