This chapter critically analyses free-form generative parametric design techniques to evaluate the effectiveness of VPL (Visual Programming Language) systems, applied to existing high-geometric/formal complexity artefacts. The paneling of the South facade of the Institut du Monde Arabe (IMA) in Paris, designed by J. Nouvel, was chosen as a case history. This is to examine how through a complex kinematic modelling, the sunshine of indoor environments can be effectively controlled. The chapter focuses on reproduction, through reverse engineering techniques of the façade-type panel, through the most widely-used VPL platforms that determine algorithmic relationships. The generative parametric algorithms developed for the IMA Moucharabieh, indicate that identical rules can govern different geometries; in contrast, identical geometries can arise from completely different algorithmic formulae. Finally, the integration with the most widely-used BIM applications, is used to critically evaluate interoperable workflows.