Discrete MFG company moving to ETO project

Hello All

I am new to Oracle support community.  I am looking for best practices for set up and planning purposes for ETO (Engineer to Order) product.  Currently this process is very hard to track and determine what stage of the planning cycle it is in and how to manage the resources.  So we design the product and MFG it all of which is approx a 4 month process on average.  So how can we attempt to schedule and set up such a process when a BOM and routing steps wont even be known until design is complete approx 6-8 weeks.  And