This Simple Process Flow Diagram is a process-description diagram. These diagrams are made up of blocks (often rectangular) linked together by arrows. The blocks contain details about a single step in a process. As a result, the aid of the block in keeping the content of a process concise. A Simple Process Flow Diagram is a flowchart that depicts the connections between major components in an industrial plant. Although the concepts are sometimes applied to other processes, they are most commonly used in chemical engineering and process engineering. They depict a process using a series of symbols and notations.