Recently, a computer program was developed which computes the theoretical trajectory of a store in the complex flow field after release from an aircraft flying at subsonic speeds. However, the engineer still had the exceptionally difficult problem of preparing the source and sink models which are part of the computer program input.Views of the interactive graphics console illustrate how an interactive graphics computer program (SOURCE) is used to prepare source and sink theoretical aerodynamic models for the aircraft fuselage, nacelles, fuel tanks, and store bodies. Use of this interactive graphics computer program reduces the calendar time required to develop a source and sink model from approximately 2 weeks to one hour. This reduction in required calendar time permits theoretical store separation analyses to be conducted for a store in the early development program when the store shape is frequently being changed.