Typical applications in the fields of the so-called Gmrzcf CWW#e5 need massive parallel computer system architectures. Tools like parallel debuggers, performance analysers and visualizers help the code designer to develop efficient parallel algorithms. Such tools merely support the development cycle. But the engineer who makes use of parallel high-performance computing applications, e.g. numerical simulation algorithms in Computational Fluid Dynamics (CFD), must be supported in his engineering work by another kind of tool. A user tool for the production cycle is required because conventional suggestions rely on serial batch-oriented procedures which have significant drawbacks, and therefore, they are not suitable to make use in nowadays High-Performance Computing (HPC). This paper presents the principal idea of the VIPER tool concept which enables the engineer who is sitting at his graphic workstation to interact with the parallel simulation algorithm which is running on a remote parallel computer system. Parameters of theoretical model and of the numerical method are considered as objects and available for Wme observation and Wme modification via the graphical user tool interface. First performance results are shown with the VIPER tool prototype implementation applied on the parallel Navier-Stokes solver PARNSFLEX which was running on an Intel Paragon XP/S multiprocessor system.