Keir,
thank you very much for your response, before to give a comprehensive answer to your suggestion, I will deepen on the help file to understand better the different types of associations, and the relative conjunction from SAP side.
But you have hit the mark, the main question is to find a best practice, to avoid the generation of a lot of different drawing numbers, at least for the early stages of development, this also because we are in the middle, of a project for the personalization, by PTC and Head quarter in Germany, In this phase only macro problem (More related plus on simple SAP production management, and it's products life cylce management are the focus, but not all the aspects and problems on the start-up phase of development more over related to different plants and locations.
Thank you very much, I appriciate however, that we will continues to deepen on this topic, even after my comprehensive answer.