Flowchart – A Quick Guide

A flowchart is a graphical representation of an algorithm, workflow, or process, with different types of boxes representing different types of steps, and arrows connecting every two steps. This representation facilitates the illustration of solutions to known problems. Flowcharts are widely used to analyze, design, document, and operate processes or procedures in many fields.

What is a Flowchart?

Flowcharts can be used to design or document a number of simple steps or procedures. Like other diagrams, such diagrams can help visualize what is happening and make it easier to understand the process in between. Although there are many variants of flowcharts, each with its own way of labeling, most have the following two symbols.

• Step. Often referred to as “activity” and usually represented by a rectangle
• Decision. Often referred to as an “activity” and usually represented by a rectangle Often represented by a diamond

Advantages and Disadvantages of a Flowchart

• Advantages: intuitive, easy to understand, easy to find errors in the algorithm, can be directly translated into a program.
• Disadvantages: It takes up a lot of space. Due to the use of flow lines, it is too flexible and unconstrained. Users can turn the flow at will, causing difficulties in reading and modifying the program, which is not conducive to the design of structured programs.

Cross-Functional Flowchart

Cross-functional flowchart is often used when a flowchart is divided into different horizontal or vertical sections that are used to describe different control units. A specific control unit will appear as an icon along with a specific section.

Cross-functional flowcharts allow the mapper to correctly assign responsibilities to “execution steps” or “decisions” and show the responsibilities of the component units for each different part of the process.

The Standard Symbols of Flowchart

Flowchart commonly used symbols in order to make the flowchart expressed in the content for others to accurately and comprehensively understand the need to use common, unified flowchart symbols in the diagramming.

At present, the International Organization for Standardization (ISO) and other institutions have flowchart symbol standards can be used as the basis for drawing, such as the need to use this standard in the actual work of graphics and other symbols, should consider its universality, try to use the community has and common, in the case of innovation must indicate the meaning and use of these symbols, and pay attention to the same diagram and later in the actual drawing to maintain the necessary continuity, and Reduce unnecessary types of symbols.

The following table lists the most common flowchart symbols.

shape	name	describe
	Process symbolFlowline (Arrowhead)	Used to express the order of the process, with a line connecting one symbol to another. If it is not the standard top-to-bottom, left-to-right diagram, an arrow will be added .
	start-stop symbolTerminal	Used to indicate the beginning and end of a program or subroutine. Often represented by a rounded rectangle . It is usually marked with “start” or “end” or other relevant words such as “submit enquiry” or “accept product”.
	programProcess	A series of programs are represented by rectangles to change the value, form, and position of data.
	decision-makingDecision	A rhombus is used to display a conditional process, which is used to determine the next step according to the situation. Usually a “yes/no” or “true/false” value to decide.
	input OutputInput / Output	The process of data input or output is marked with a parallelogram
	annotationAnnotation (Comment)	To supplement additional information on a step, a dashed line can be used to connect a semi-closed rectangle to the symbol to be annotated  .
	Process definedPredefined Process	Use a rectangle with 2 left and right vertical lines to represent a process that has been defined elsewhere.
	same page referenceOn-page Connector	Use a small circle with letters to connect the target processes on the same page.
	page change referenceOff-page Connector	Use an inverted house shape to indicate the target process is drawn on another page.

 

Other Additional Symbols

In addition to the above basic symbols, examples are as follows

shape	name	describe
	data file or databaseData File or Database	The database is represented by a cylinder.
	fileDocument	The file is marked with a rectangle with a wavy bottom.
		Use multiple rectangles with wavy bottoms to mark multiple files.
	showDisplay	The process of displaying the results is marked with a left triangle square right rounded corner shape.
	manual operationManual operation	Use a right-angled semi-trapezoid to mark the process that requires manual entry, correction or operation.
	initializationPreparation or Initialization	The initialization or preparation process is represented by an elongated hexagon.

Tips for Creating Flowchart

The following guidelines must be followed when preparing flowcharts.

• Standard symbols should be used when drawing flowcharts.
• Make sure the flowchart has a starting point (or beginning) and an ending point (or end).
• Avoid crossover of process lines
• The usual orientation of a flowchart is top to bottom or left to right.
• The terminal symbols, i.e. START/BEGIN or STOP/END should have only one flow line.
• The flowchart should be neat, clean, and easy to understand. There should not be any ambiguity.
• Only one process line should come out of the process symbol.
• Only one process line goes into the decision symbol, but there can be two or three process lines, one for each possible answer, leaving the decision symbol.
• If the flowchart is long and complex, connector symbols should be used to reduce the number of process lines.
• Use annotation symbols to describe the steps more clearly.

Learning Flowchart by Examples