The proposed LAWENDEL project aims to develop laser welding process for aerospace applications by combining expertise in model based process design at the University of Manchester with a systematic experimental approach by the project coordinator, Helmholtz-Zentrum Geesthacht. The objective is to study the laser weldability of a newly developed Al-Li alloy, to determine the process parameters needed to obtain consistent laser welds, and to compare the mechanical behaviour with the conventional aluminium alloys series. The study will emphasize the microstructure characteristics and the mechanical properties of the weld joint to gain an understanding of the underlying factors controlling the performance of the welds. During the demonstration phase of the project, the developed LBW technology will be applied for welding a stiffened flat panel out of the new Al-Li alloy, named demonstrator B1, in order to evaluate the industrial application. The skin and the stiffener will be provided by Topic Manager. The demonstrator B1 is a rectangular aluminium panel 384 mm x 742 mm (AA2198) with 4 stringers out of AA2196 spaced in equal distances. Three demonstrator panels will be welded by using the optimized parameters defined from the previous phase and then inspected by NDT in order to assure the structural integrity. The innovative combination of state of the art modelling and experiments will enable physics based optimization of the welding process with greatly reduced time and cost compared to traditional trial and error methods.