*2.5. Simulation Modeling in Energy Management*

Simulation modeling is a suitable tool to design and verify various rules and strategies for power and energy management, to find the optimal production setup in terms of energy consumption, and also for the analysis of energy consumption itself. Its use is quite widespread:


In these sectors, simulation models are created for both systems consisting of a single machine or a multistage machine [66,76] and for entire production plants [69,77,78], sometimes including, for example, the operation of buildings or other supporting technologies [26,66,68,79].

The main motive for using simulation modeling is almost always to analyze energy consumption and reduce costs or energy intensity to resource depletion or global warming. To reduce consumption, the following approaches can be identified primarily, namely, optimization of machine control functions, optimization of parameters in production, and the design of energy-efficient production at the beginning of its design. However, individual approaches and models are quite specific and focused on addressing a particular problem and need [26,70,77]. In this context, their wider use is thus rather limited and a comprehensive view is usually missing—the greater integration and interaction of various factors and parameters such as production equipment operation, process parameters, building operation, price tariffs, etc. For example, if parameters such as operation and management of individual machines, production batches, efficiency, and number of operating machines, failure rates, building operation, etc. are integrated into the model in grea<sup>t</sup> detail, parameters such as price tariffs or constraints on the energy supply side are no longer integrated into the model [68,69,78]. On the other hand, if parameters such as price tariffs or supply-side constraints are already integrated, other parameters are not integrated to a sufficient extent or in sufficient detail [71,72,75]. Another situation is that models only integrate certain types of energy such as electricity, for example, [69,72,73].

One reason why other different factors and parameters are not integrated into the models may be that simulation tools still provide their users with limited options in some respects, despite some progress in recent years [80]. However, the key point remains that simulation modeling allows companies to analyze and optimize consumption [26,69,70] as well as validate different energy optimization strategies [2,81]. Moreover, without having, for example, APS software, which they often cannot even buy for financial reasons, it is also important that, unlike APS software, simulation modeling allows for the inclusion of uncertainty in the model (e.g., in the form of machine failure rates or production quality) [68,70,77]. Another benefit is that simulation modeling enables "what if" analyses [78,82].
