The process for accurately estimating product reliability early in the development process can be a difficult and costly task. Traditional methods like Reliability Prediction Models and Life Testing Strategies yield beneficial results when relative information is known about the product that is to be analyzed. When there is minimal information (e.g., prior failure rates, etc.), such as in new concept design, these above reliability methods have limitations. For these cases computer simulation technology has proven to yield valuable results. This paper will demonstrate analysis procedures for assessing the margin and reliability of product design in the early product development stage. This analysis process is composed of requirements definition, a mathematical model, model validation, parameter diagram, design of experiment (DOE), response surface, and optimization. The analysis process shows its impacts, in the following areas: reducing the product development cycle, reducing cost, increasing confidence, and estimating product reliability. This is particularly important early in the concept development process.