Inventory orgnization structure

Hi

Client is in construction business.We are implementing Financials,Project Costing,Project Billing,Inventory,Purchasing and HRMS.Do we need to have any project manufacturing set up to be done.

They have one central warehouse and the project warehouses..

How do i define my inventory structure .

Like how many inventory organizations,sub inventories and locators.

Do i need to define each project warehouse as inventory organization.

In that case do i need to attach the items defiend in the master org to all these inventory orgs which determine project warehouses

I beleive for few items they are using locators.