The quantitative prediction of macroscopic mechanical properties of materials requires the consideration of the material microstructure. This talk focuses on metallic material systems with lamellar microstructures, such as NiAl-Cr(Mo) or binary Fe-Al. These consist of individual domains in which the materials constituents are arranged in fine layers (thickness in the micrometer range) with a distinct layer normal direction. The layer interfaces act as obstacles for dislocations, leading to dislocation pileups which influence the macroscopic stress response via a size-dependent evolution of the defect structure and the corresponding back stress in the laminate on the micro scale. The back stress leads to an increase of the macroscopic yield stress through size-dependent kinematic hardening, which is observable upon load reversal. In order to model the material system, we make use of a two-scale homogenization approach. For this, we describe the microstructure of one domain as a periodic rank-1 laminate, which allows for efficient mathematical description of the mechanical behavior of one domain. Exact localization relations are used to explicitly resolve the local stress and strain fields. Within the framework of gradient crystal plasticity, the yield conditions take the form of a system of coupled Fredholm integro-differential equations for the plastic slip, which is solved semi-analytically under consideration of the loading-unloading conditions. This size-dependent modeling approach allows for a physically motivated description of the Hall-Petch and the Bauschinger effect, taking both the lamella widths as well as the lattice orientation of the different constituents into account. The capabilities of this method are demonstrated by means of multiple examples where the influence of different microstructure parameters are discussed.