I have one company with two warehouses A&B. The company buys raw materials and stocks in these two warehouses. The company also has three stores at different construction sites where the raw materials are assembled into structures. I have created one shop and the two warehouses. I need help on how to do full structuring of this material transaction such that materials are bought stocked in A and B, then what is needed at site X, Y and Z are transfered  and production in done at the respective sites. At some point I may also need to return excesses from the site stores to A and B. I may need to monitor two points of despatches from A&B and also from any of the site stores to know material usage on the site.

My idea is to consider the stores as warehouses too. This makes many warehouses and my confusion also is whether to consider the site stores as customer locations. Can some one help me out?