The mental workload associated with work activities is a key factor affecting the performance of human resources in labor-intensive construction operations, in turn impacting work behavior. While most accidents in construction are caused by unsafe behavior, modeling behavior in construction projects remains challenging and relatively unexplored. Here, human cognition is incorporated into the design of construction operations to analyze the mental task demands associated with various designs. A framework that integrates cognitive modeling with a simulation-based decision-support system capable of analyzing existing and non-existing operations in a simple and automated manner is proposed. The superiority of the proposed framework is that it eliminates the need for prior knowledge of the underlying cognitive theories. Functionality of the developed framework was evaluated following its application to a case study of welding operations, where the proposed method was shown to successfully evaluate the trade-off between mental workload and productivity for different operation scenarios.