How to model locations on inventory

How to model locations on inventory

We are using the inventory modules in CRM, but we have a problem modeling locations on inventory.
Currently we have multiple warehouses and we need to separate quantities of products in each location. 

We tried including a custom field called location and putting the product multiple times. This works until we move stuff from one warehouse to the other (how can we model that?)

What is the best way to model locations on inventory?

Thanks in advance for any suggestions on this

Maria Velasco