Over the past decade, the use of numerical modeling and simulation in the design and development process has grown dramatically. Increasingly sophisticated user requirements coupled with ever decreasing computer costs fueled this growth. During this time, commercially available analysis codes have improved, becoming both more powerful and user friendly. Many programs, once requiring mainframe computers, now can be run on PC platforms. One such program is SINDA/G, a long accepted standard for thermal analysis in the aerospace industry. This paper describes SINDA/G's evolution over the last 10 years to meet these increasingly demanding and challenging user needs.