How to maximize profit if call forecast become less in call centre BPO?

By doing three actions

1- Analysis of the IVR calls and understand the real call scenario in the IVR. IVR is the black box and using a proper reporting tool will show you the number of calls on each IVR branch and after this you may need a real revamp for the IVR

2- Analysis of calls taken by agent through AHT , AST , Wait time

3- Introduce new products and services through your call center

Well it depends , if it is less than forecast then you need to adjust your forecast and adjust manning requirements. This can be done by offering staff a Half Time opportunity till you get the real call volume to decrease cost. 

If it's a Sales Call Center then you need to make sure your Revenue per call increases that can be done by maximizing per order per call. 

To concentrate and do the best on the actual calls and convert them into sales.