IVR system utilization

Dear all,

Can anyone tell me how can we measure the current system utilization of an IVR system ? If the system capacity of an IVR system is mesaured in the value BHCA it can handle, then is that right if we take the utilization as (current BHCA of the system)/(BHCA the system can handle), then how do we obtain the current BHCA, the average BHCA in last six months or … ?

Can anyone clarify for me.

Many Thanks & Regards,
William.