For example, the input could be provided by a user like at an ATM machine or in a form online or it could data provided by an instrument like a temperature read. The program will have code to interpret the input and generate an output.
The output could be a series of things: a message printed on a the user interface or data handed off to another process. There are two different types of approaches to symbols in data flow diagrams: Yourdon and Coad and Gane and Sarson. In the Yourdon and Coad way, processes are depicted as circles, while in the Gane and Sarson diagram the processes are squares with rounded corners.
Most of the flowchart symbols shown here are for use in very specific applications, such as a data flow diagram used for computer programming. Unless you have specialized knowledge and your diagram is being developed for a peer group with similar knowledge, it's best to stick to basic flowchart symbols. If more than the most basic flowchart symbols appear in your diagram, it is good practice to include a legend or symbol key.
Sticking with these two primary flowchart symbols is the best way to ensure that your diagram will be easy to understand. Sign up for SmartDraw free Start Now. A visual workspace for diagramming, data visualization, and collaboration.
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Lucidchart is a collaborative workspace that brings remote teams together in real time. Each symbol has a specific meaning and context where its use is appropriate. If you get confused while drawing your flow chart, remember that most charts can be drawn with just a few common symbols, which are listed below. Want to create a flowchart of your own? Try Lucidchart. It's fast, easy, and totally free. These flowchart shapes and symbols are some of the most common types you'll find in most flowchart diagrams.
Represents the input or output of a document, specifically. Examples of and input are receiving a report, email, or order. Examples of an output using a document symbol include generating a presentation, memo, or letter. The flowchart path may then split off into different branches depending on the answer or consequences thereafter. Frequently used within complex charts, this symbol connects separate elements across multiple pages with the page number usually placed on or within the shape for easy reference.
Placed along with context, this symbol adds needed explanation or comments within the specified range. Graham, Director of Formcraft Engineering at Standard Register Industrial, adapted the flow process chart to information processing with his development of the multi-flow process chart to display multiple documents and their relationships.
Douglas Hartree in explained that Herman Goldstine and John von Neumann had developed a flowchart originally, diagram to plan computer programs.
Flowcharts became a popular means for describing computer algorithms. The popularity of flowcharts decreased in the s when interactive computer terminals and third-generation programming languages became common tools for computer programming.
Algorithms can be expressed much more concisely as source code in such languages. Often pseudo-code is used, which uses the common idioms of such languages without strictly adhering to the details of a particular one. Nowadays flowcharts are still used for describing computer algorithms.
Sterneckert suggested that flowcharts can be modeled from the perspective of different user groups such as managers, system analysts and clerks and that there are four general types: [10]. Notice that every type of flowchart focuses on some kind of control, rather than on the particular flow itself.
However, there are several of these classifications. For example, Andrew Veronis named three basic types of flowcharts: the system flowchart , the general flowchart , and the detailed flowchart. In addition, many diagram techniques exist that are similar to flowcharts but carry a different name, such as UML activity diagrams. The following are some of the commonly used shapes used in flowcharts. Generally, flowcharts flow from top to bottom and left to right.
A typical flowchart from older basic computer science textbooks may have the following kinds of symbols:. A number of symbols have been standardized for data flow diagrams to represent data flow, rather than control flow. These symbols may also be used in control flowcharts e. Any drawing program can be used to create flowchart diagrams, but these will have no underlying data model to share data with databases or other programs such as project management systems or spreadsheet.
Some tools offer special support for flowchart drawing. Many software packages exist that can create flowcharts automatically, either directly from a programming language source code, or from a flowchart description language.
On-line web-based versions of such programs are available. Skip to main content. Control and Logic Elements 8. The others are optional and often only confuse people. This shape tells you where the flowchart begins and ends. It shows the entry point of your flowchart and the exit point. To designate the start of your flowchart, you would fill this shape with words like Start or Begin.
The words you use are up to you. To designate the ending point of the chart, this shape is filled with words like End , Exit , or Return.
Usually a flowchart has one starting point. However, a flowchart can have as many ending points as needed. Sometimes you see this shape drawn as an oval as shown below. That is fine. You read a flowchart by following the lines with arrows from shape to shape. The lines with arrows determine the flow through the chart.
Flowcharts are usually drawn from top to bottom or left to right. Numbering shapes is optional. Numbering is helpful if you have to refer to a shape in a discussion. Numbering does not determine the flow of control. That is determined by the lines with arrows. If two lines cross, you ignore the perpendicular line and continue following the line to the next shape.
If there may be confusion as to the path, you can insert a bridge or crossover, which is a little bump on crossed lines. In most flowcharts, the rectangle is the most common shape. It is used to show a process, task, action, or operation. It shows something that has to be done or an action that has to be taken. The text in the rectangle almost always includes a verb. A decision asks a question. The answer to the question determines which arrow you follow out of the decision shape.
For example, in the shape below, if it is cloudy, you follow the arrow down near the word Yes. If it is not cloudy, you follow the arrow to the right near the word No.
The arrows flowing from the decision shape are usually labeled with Yes , No or True , False. But you can label them any way you want as long as the meaning is clear. This shape has one input arrow. It is usually at the top, but can be on any corner.
The decision shape can have two or three exit points. If you need more than 3 exit points, then you can use either of the methods shown below. If you need to connect to another page or another section of the chart, and can't draw a line, you can use a circle.
You draw the line to the circle and label the circle with a letter.
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