Like input-output symbols, process boxes have a single line connecting it to the previous flowchart step and a single line leading to the next one. A flowchart may contain any number of process boxes.

A flow chart, or flow diagram, is a graphical representation of a process or system that details the sequencing of steps required to create output. A typical flow chart uses a set of basic symbols ...

However, the simple flow chart of Input, process, and output are still used to visualise how the system performs.