The Master Thesis project concerns the creation, validation and optimization of an application, based on the Matlab Graphical User Interface (GUI), used to process data for an experimental modal analysis. A real-life application case on a carbon fibre monocoque is eventually presented. Modal analysis is a tool to understand and describe the dynamic behaviour of a structure, on the basis of its modal parameters: damping, natural frequencies and mode shapes. The work is mainly divided in three parts: the first one is an introduction to vibrating systems, starting from a single degree of freedom and ending with the explanation of a modal parameter extraction technique used for multi-DOF systems, and therefore in the app, called LIPEZ.