Simulation is a powerful tool that helps decision makers in business and industry to solve difficult and complex problems, reduce cost, improve quality and productivity, and shorten time-to-market. However the technology is still underutilized in many applications due to several reasons. In this study we address these issues using a knowledge engineering approach, i.e. develop efficient and robust models and formats to capture, represent and organize the knowledge for developing conceptual simulation models that can be generalized and interfaced with different applications and implementation tools. The research fits into a larger project effort that aims to create a sustained research program on knowledge-based simulation.