²It should be noted that the “zooming in” of scope in a P&ID does not necessarily mean the scope of other areas of the process must be “zoomed out.” In fact, it is rather typical in a P&ID that the entire process system is shown in finer detail than in a PFD, but not all on one page. In other words, while a PFD may depict a process in its entirely on one piece of paper, a comprehensive P&ID will typically span multiple pieces of paper, each one detailing a section of the process system.