Business simulation games are widely used in the classroom to provide students with experiential learning opportunities on business situations in a dynamic fashion. When properly designed and implemented, the computer simulation game can be a useful educational tool by integrating separate theoretical concepts and demonstrating the nature of actual business decisions. This article presents the author's reverse engineering approach in developing a simulation game for an operations management course. With the ultimate goal of enhancing student learning, the project's objective was to develop a focused game with easy to use tools and controls that could be played in the last three weeks of a semester. Based on an old simulation game, PROSIM III, the new system eliminated rarely used modules and complex rules, and focused on the planning and scheduling aspects of the original game. New analysis tools and attractive screens were added and the simulation process was simplified by employing Internet technologies. Survey responses showed that the new system, PROSYS, was well received by the students. The methodology, findings and experiences presented in this article should be beneficial for other instructors considering similar projects.