A new micro/macro computational strategy is proposed for the analysis of structures which are described up to the "micro" level, such as composite structures. This strategy is intended to overcome standard homogenization techniques coupled with a local re-analysis, at least for several domains of interest. The description of micro and macro quantities is performed on the interfaces arising from the decomposition of the structure into an assembly of sub-structures and interfaces. Two examples of such a description are detailed; both are built from a kinematic point of view. Lastly, the performance of this multi-scale computational strategy is shown on an example of a 3D, strongly-heterogeneous structure.