1. An object entity stored in a non-transitory computer-readable storage medium within an object oriented programming environment for programming functionality for use with a user interface system for a process control system, the object entity comprising: a first portion defining graphics for a depiction of a process plant element of the process control system via the user interface; a second portion identifying a data source for data indicative of on-line operation of the process plant element to be displayed via the depiction wherein data indicative of the online operation of the process plant element is retrieved from the data source when the graphics for the depiction of the process plant element are rendered for display via the user interface so that the depiction of the process plant element is displayed via the user interface in a manner indicative of the on-line operation of the process plant element; and a third portion defining a method to be implemented to simulate on-line operation of the process plant element; wherein the first portion is set forth in a declarative format; and wherein the object entity within the object oriented programming environment operates to depict both on-line and simulation operation of the process plant element that includes displaying data calculated from the simulation via the depiction when the graphics for the depiction of the process plant element are rendered for display via the user interface.