Human operations play a vital role for the resilience of power grids. While past research concentrated on performance in cascading failures, this work proposes a system model that focuses on assessing the impact of the performance of operators in grid operations and restorations. The operator model developed for this purpose addresses human performance and variability by accounting for stochastic durations, potential errors and alternative responses, and the probabilities of these outcomes. Discrete event simulation is the assessment framework, with the model implemented in MATLAB Simulink in conjunction with a dynamic power system model. A re-energization cell provided by a Swiss generation system operator is used for a case study demonstration of the simulation model, which produces distributions of the total restoration duration and restoration success rates while identifying the parts of restoration plans that could be modified to enhance restoration performance. The overall outcomes of the case study suggest that the human element can be treated practically in grid simulations in order to produce findings that will increase grid resilience.