While it may be tempting to use extremely detailed 3D solid models of complex assemblies in our simulations, the practical analyst understands how to simplify the geometry appropriately. Doing so helps us obtain useful results in a reasonable amount of time that can help guide our engineering and design decisions. In this course on “Geometry Representation,” we’ll go through the thought-process involved in determining how much of our assembly or system to include in the simulation. We need to consider the implications of truncating our domain with boundary conditions. Also, we’ll explore alternative methods to 3D solid modeling, such as using beam, shell, or 2D profiles that can speed up the solutions considerably when applicable.