Simulation beginners often spend a great amount of time to accumulate the knowledge as well as the experience to overcome the technical complexity of computer simulation. Limited by time availability, classroom instructions usually contain little simulation statistical analysis after many hours of simulation modeling and programming. However, the success of a computer simulation project depends greatly on the effectiveness of simulation statistical analysis. Internet asynchronous web learning reduces the workload of classroom teaching. To help the novice learn better simulation problem solving, this research addresses designing the usability into computer-based training (CBT) environment by focusing on the simulation experience and the interaction design. A prototype asynchronous web CBT system was built for validating our design via a three-stage formative usability evaluation.