Abstract : Abstract : The aims of this work is, firstly to propose a new assimilation of the visibility relationship of VBOOL in the UML (Unified Modeling Language) standard language for modeling and specifying objectoriented systems. Secondly, to complete UML by an oriented viewpoint method to get a complete software engineering process. U_VBOOM method represent an adaptation of VBOOM (View Based Object-Oriented Method) integrating the UML notation. The new U_VBOOM method keeps main VBOOM concepts and integrates to its development process strong points of UML such as use cases and a new stereotype <> that allows with the aggegation relationship to implemente the visibility relationship. This new approach encourages the multi-targets code generation and improve the process of development proposed by the VBOOM method.