AgentsASA formula

When working with some of our Call Centre customers, I'm seeing use of AgentsASA being used, whilst we have the Agents formula it would be good to have the AgentsASA as a formula to use.

The definition of the formula is not too dissimilar to the Agents as it uses ASA rather than SLA.

I've attached the Agents and AgentsASA formula from a commonly used Call Centre Excel add-in.