This chapter provides an overview of diagramming techniques that can be used to provide a structural representation of the system. The main methods used in DES are process flow diagrams, process maps and activity cycle diagrams. Event graphs and state charts are also covered in this chapter for reference.

As stated in chapter 1, DES takes a systems approach to create an explanatory model consisting of individual processes and their interdependencies. The explanatory model will provide a structural representation of the system. This structure enables a variety of future behaviours and provides a representative that helps explain the simulation model results. In general, pure explanatory models are seldom found, and in a DES model, we usually depend on descriptive sub-models (chapter 5) to describe individual relationships and variability in an aggregated form. For conceptual modelling, in regard to the explanatory model, the emphasis should be on representing those processes which are decisive for system behaviour.