Last Stage Product Identification

Hi;

We have scenario; Final product developed after passing through different routing steps for example R1, R2, R3, R4, and R5. Different products are developed at R5 steps, where in all these products R1, R2, R3, and R4 steps are common at steps R5 is different at this step it is decided which product is to be developed finally.

At the time of creating formula, receipe and document you have to define the product, the problem is that in this case we can't work if the final product is decided at last stage R5 than how can we create  formula, receipe and document to start/relase the job to issue ingredients. Please advice how this can be achievied in OPM.