A Process Flow Diagram (PFD) is a form of flowchart that depicts the interactions between various components in a manufacturing facility. Though its ideas are occasionally extended to other processes, it is most commonly employed in chemical engineering and process engineering. It's used to record a process, enhance an existing one, or design a new one. It is also known as a Process Flow Chart, Flowsheet, Block Flow Diagram, Schematic Flow Diagram, Macro Flowchart, Top-down Flowchart, Piping and Instrument Diagram, System Flow Diagram, or System Diagram, depending on its application and content. They illustrate a process using a sequence of symbols and notations. The symbols vary, and the designs might range from crude, hand-drawn scrawls or sticky notes to professional-looking schematics.