Simulation as a method to model manufacturing processes is often not sufficient to solve operational decision problems in an optimal manner. In addition, optimisation methods and algorithms are required. This standard discusses the integration of simulation and optimisation to support decision-making in operations. It provides a categorisation of the different ways to combine simulation and optimisation, and illustrates, based on examples, which category fits to which decision problem. Furthermore, it shows what needs to be considered when combining these two techniques to make the results applicable to operational decision problems.