I have Odoo version 8 and I am testing placing orders. However, in the 'view delivery order' page when I press check availability button it makes the state ready to transfer from either waiting for availability or partially available. Could someone confirm this is default behaviour or not ? Also, what if there is not enough stock available? then why would it change to ready to transfer ? could someone possibly explain how the process works in Odoo ? 

The process I followed to recreate my dilemma:

Sales Orders => Create => fill in info => save =>confirm sale=> view delivery order => check availability => state shows ready to transfer.

Product chosen in the order has 0.0 availability and ordered 1 if it makes a difference. Shouldn't it stay on waiting for availability or partially available?