A common asked question is 'Why does a certain HG member has more abandoned call than all other members?'

This is because of that HG having a simultaneous ring type. For a standard HG with a simultaneous ring type the telephone system will automatically assign any abandoned call (a call that's terminated by the initiated calling party) to the last member added to the HG's membership. Rather than all members been assigned with abandoned calls, which would also mean assigning them all with Inbound calls, only the last added member into the HG's membership gets penalised with the abandoned call. 

If the member is engined an on DND state or busy on an active call, then the previous added member gets penalised with the abandoned call instead.

NOTE: This is a behaviour that is entirely controlled by the Telephone system