Order creates more deliveries than 1

 Hi,

     The sales order creates more than one delivery when user creates an order .When i try to replicate the issue , it doesnt happen.

Could the experts put their thoughts together as to what set ups should be checked for this .What setup is required for not splitting the delivery for a sales order and also what set up is required for splitting the SO in multiple deliveries.The user gave this info-

A split in more deliveries must be done only when :

1. We pick on more warehouses (YC and SC)

2. When on-time-location is not the same for all lines