Figure D.17 provides an example FunctionalEntity model that could be applied to the single-board computer from the Asset example (MyRaspberryPi). The model shows a subtype of FunctionalEntityType that represents an execution engine that can run generic function blocks. The ExecutionEngineType includes the capability of loading libraries of function blocks, where each function block would be a FunctionalEntity. The model includes a Method that is used to load function block libraries and a Method to load a program that is executed by the ExecutionEngine. ExecutionEngineType will be used to illustrate various aspects of the FunctionalEntity model in the following sections.