Process Flow

Process flow, also known as PFD’s (Process Flow Diagrams) work as road maps for chemical processes as well as multiple different engineering disciplines. They are essentially complicated flow charts describing certain functions, large equipment, etc.

Process Flow Diagrams often include the following:

• Process flow directions
• Major equipment information and what is used in different stages of production
• Piping used for chemical processing (or any other use) that is over a certain size
• Bypass and circulation lines
• Control valves and process-critical block valves
• Connections between other systems on separate PFD’s (there can be several)

When using process flow in the design of a manufacturing facility, the PFD is not kept up to date after the building is complete. This is because things often change after the building is complete, usually when new procedures are implemented to make the facility more efficient. 

There are also other types of these diagrams that use different strategies to describe varying processes. Some of these are:

• Block Flow Diagrams show what is to be done in a general sense. These don’t include how machines work in a process for example, rather, they just focus on big ideas that need to be completed.
• Line Flow Diagrams often are rather large ideas, yet they are small in stature. This is because they describe things like machine details or a manufacturing process in one single line connected with arrows directing the user where to go next once one process has been completed.
• Pictorial Flow Diagrams establish key processing steps for things like concrete manufacturing. Showing images of the process is often helpful when visualizing one’s tasks, yet there is no description aside from the images. 

Process Flow is used in business management as well. Just like the engineering side of things, the people who make business Process Flow Diagrams are technical writers that interview subject matter specialists. The diagrams look quite a bit different regarding symbols as meanings are often prescribed by the shapes of the boxes rather than the complicated and numerous symbols in engineering PFD’s.  

The benefits of using process flow are numerous with some of the most beneficial being communication, proper documentation, and effective analysis (to help with waste management).