This contribution presents developments and trend for the structure of new simulation systems, or for extensions of existing simulation systems, in order to handle structuraldynamics systems in an adequate manner. The paper first introduces the CSSL standard for continuous system simulation and its consequences. In the following, discrete elements in continuous modelling and simulation; in more detail event structures are discussed and state events are classified. Thereby, the class of structural-dynamic systems is introduced: State events, changing the dimension of the state space, generate structural-dynamic systems.

The paper continues with recent modelling standards in continuous modelling and simulation. There, Modelica and VHDL-AMS are leaving the classic input/output -- related modelling methods and introduce non-causal modelling on a high level, including implicit models and state events associated with state events. Both new standards, extending and replacing the CSSL standard for the model frame, emphasise on continuous and hybrid modelling; but also especially Modelica allows defining pure discrete model constructs based on events, state charts, and Petri nets.

The main chapter concentrates on new proposals for extending model frame and experimental frame of simulation systems, mainly in order to handle structural-dynamic systems properly. There, features of two competing ?philosophies? are sketched, maximal state space versus hybrid decomposition. The paper concludes with a concept for generalisation of the experimental frame, leaving the limits of pure time domain analysis.