Dynamic decision making is an important area in the modern business world. This study provides a theoretical framework for the cognitive process of dynamic decision making. The framework consists of two problem spaces and cognitive operators in the spaces. Two experiments of computer simulated management games were conducted to evaluate group problem solving as a method to increase performance in dynamic decision making. The results indicate that group problem solving is effective when the task is simple, but does not increase performance when the problem is relatively more complex. However, there is a positive correlation between the diversity of inferences and the high performance in dynamic decision making regardless of grouping. This paper concludes with candidate explanations about the interaction between problem complexity and divergent inference.