Hmmm...I think I understood. In our case we have 2 companies, 2 shops and 1 warehouse. Products are common for both shops. I guess I should go for the logical warehouses solution. Can you point out where to find information about this setup? What is a "logical" warehouse? I see there are 4 virtual

I was not clear: you cannot do this. A company cannot sell products it does not own. To track the products that the company owns, you must put it in a OpenERP warehouse belonging to the company. The fact that this warehouse's building is physically shared with another company is irrelevant.

Ok. But this is a common situation: companies sharing same warehouse and products but selling on different stores. I'm trying to achieve a configuration that allow us to manage this enviroment. After reading OpenERP books online I believe it can be achieved through virtual locations. Some advice?

Is it really two companies (different Organization numbers) or one legal entity with two names? Multi-company is mainly designed for cases where each company is a separate legal entity. As such the inventory got to be owned by one or the other with the need to create sales orders for passing the inventory to the other. If on the other hand it is one single legal entity, then the multi-company module might not be the right solution as it will cause accounting problems, such as valuation of stock. There are hacks make this module act as one company, though I recommend a multi-shop module instead

The reason being there are holding companies with multi-companies (legal entities) which each again can have multiple stores. If hacking the multi-company module to mean multi-shop it might work for some time, but you are now prevented from later adding a second legal entity.

Our companies are indeed 2 different legal entities, managed from same place, sharing a physical warehouse, but selling in 2 different shops. Both shops sell to both retailers and to individual clients, sharing products from each other on the physical stock. Right now everything is done manually and currently we indeed issue sell orders between them. What I want to know is if this can be configured on OpenERP. If yes, then if it is easy to explain and how to accomplishj. Or maybe get more information on how to get more help or online resources on the subject. Thanks @Andresen-eConsulting

Then you can decide to create two warehouses with the same location, or have the warehouse itself owned by one of them and create a location within that warehouse which belong to the alternate company. The OpenERP book have some examples: http://doc.openerp.com/v6.1/book/5/5_14_Stock/5_14_Stock_inv.html and http://doc.openerp.com/v6.1/book/5/5_14_Stock/5_14_Stock_Location_Ex.html .