During late 2013 Berlusconi decided to re-found his old party FI, while Alfano, who was PdL secretary, disagreed. I was a bit surprised when Alfano was regarded as a secessionist, and was even more surprised when he announced he was going to found a new party and dissolve the PdL.
I would have guessed he could just keep PdL for himself and for whoever wanted to stay, and clearly label Berlusconi as a secessionist.
So, (a) there was some specific provision in PdL bylaws permitting Berlusconi to "just shut it down", regardless if he still was secretary and regardless of what the members wanted? (I wouldn't be surprised if that was the case)
Or (b) there actually was some kind of vote, and it was voted to shut down?
If neither (a) nor (b), I can't understand why would Alfano consider best to found a new small party instead of keeping an established one, unless he was playing against himself on purpose.