Wire-arc directed energy deposition (wa DED) enables the rapid and efficient production of large metallic components. In addition to manufacturing parts from scratch, wa DED can be used for structural modifications of existing components. This allows for the integration of wa DED with other manufacturing processes, such as sheet metal forming or casting, leveraging their combined advantages. In this work, wa DED stiffeners are applied to reinforce Z shaped Al 7xxx profiles. Simulations are employed to optimize the wa DED stiffener production via FE solver LS DYNA. In a first step, the forming process of the Al 7xxx sheets is simulated. The resulting residual stresses serve as the initial stress state for the wa DED process simulations. This step is crucial, as previous studies on Al 2xxx alloys indicated an increased risk of cracks in the bending radius. To enhance simulation capabilities, an existing Python framework for the semi automated simulation of 2.5D wa DED structures was adapted for 3D geometries. A toolpath based slicer, developed using the visual programming language Grasshopper, was employed to generate the splitting surfaces necessary for dividing the geometry into individual layers. In addition to these surfaces, the slicer produces essential LS DYNA input files, including those that define the heat source path and the start and end times of individual welding seams. Using the combined Python framework and slicer, thermo mechanical process simulations of the wa DED stiffeners are performed. All simulations are based on predefined flow curves, identified through dilatometer tests at different temperatures. Simulation results of various manufacturing strategies – such as modified toolpaths and preheating temperatures – are compared based on temperature distribution, stress development, and deformation, in order to identify the most favourable approach. For future simulations, further improvements are planned. To enhance the accuracy of residual stress and deformation predictions, advanced material models will be incorporated, including for example the effects of precipitation strengthening.