During the phase of instrument design and until integration, a number of DFS products are defined and prepared, including Phase II and archiving tools, ETCs and data reduction software. Preliminary requirements are defined by the Instrument Responsible. As described in the VLT Science Operations Plan [7], instrument development projects are realised by mixed teams formed under the responsibility of department heads in the Instrumentation Division in Garching. For DFS products, an instrument control software specialist (VLT/INS) and a data analysis specialist (DMD) are member of the team.