For predicting industrial automation network performance, a method generates algorithm parameters in a first standard format for a network calculus model from design data for a network implementation. The method generates the network calculus model from the algorithm parameters. The network calculus model models worst-case performance for the network implementation. The method generates model parameters in a second standard format for a network simulation model from the design data. The method generates the network simulation model from the model parameters. The network simulation model models probabilistic performance for the network implementation. The method executes the network calculus model to determine network calculus results. The method executes the network simulation model to determine network simulation results. The method determines a system policy difference between the network calculus results, the network simulation results, and the system policy. The method updates the design data based on the system policy difference.