This Small Business Innovation Research (SBIR) Phase II project proposes the development of a software interface to allow convenient access to the modeling, simulation, and estimation capabilities of Scop from within PROPHET. The goal is to provide a significant enhancement to PROPHET's modeling capabilities, while at he same time maintaining the flexible data handling and display features of PROPHET that its user community requires. This goal will be accomplished by; 10 designing and developing a new graphical user interface (GUI) for Scop, motivated by the GUI being developed for release 4 of PROPHET; 20 making additions to PROPHET to allow Scop access; 30 preparing associated documentation for installation and use of the PROPHET/Scop access; 30 preparing associated documentation for installation and use of the PROPHET/Scop interface; and 4) presenting a simulation training workshop on the system. Simulation is a powerful tool for under standing the characteristics of complex biomedical systems at size scales from chemical reactions to populations and the environment. By expanding the simulation capabilities available in PROPHET, this project has the potential of making significant contributions to research in biochemistry, physiology, pharmacology, toxicology, epidemiology, and other life science fields.