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What is a Flowchart?

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A flowchart is a diagram made up of rectangles, ovals, octagons, and other shapes to visualize the flow of a program or depict the steps a block of code will take from initialization through execution. In this tutorial, we will discuss flowcharts, how to use and create them, and how they can help software developers create better software.

Overview of Flowcharts

Flowcharts – or flow charts as you may see them referred to – are a great tool developers can use to map out the processes and logic of a piece of software or block of code. Combined with pseudocode – a mix of human language and code – flowcharts act as a sort of blueprint programmers can reference to ensure programming logic is correct and obtain an overhead view of either a module in a piece of software or the entire program in some instances.

Flowcharts exist outside of software development as well. In fact, you can find flowcharts in virtually every type of business, though they may be hiding under different names. Flowcharts are part of business processes, and exist in specialized forms, such as:

  • Process Maps

  • Process Flowchart

  • Process Models

  • Process Flowcharts

  • Process Flow Diagrams

  • Business Process Models

  • Business Process Maps

Flowcharts are cousins to other diagramming models, such as Data Flow Diagrams and Unified Modeling Language Activity Diagrams, to name but a few.

For our purposes, we will focus on basic flowcharts as used in a software development environment.

Flowcharts pre-date modern computers and software development, getting their start well before the advent of computers back in the early 1920s. Created by two engineers, the “Flow Process Chart” was introduced to The American Society of Mechanical Engineers (ASME). The concept was used to make workers and business processes more efficient and then, later, was adopted for the purpose of data and information processing. Symbols were then introduced in 1947 and, around the same time, flowcharts were incorporated in software development by Herman Goldstine and John Van Neumann.

Benefits of Flowcharts for Software Developers

Flowcharts offer a number of benefits to programmers and other members of a software development company, including project managers and developer leads. While you can create flowcharts by hand, the real benefits of flowcharts come into play when developers utilize flowchart software and tools. We will discuss flowchart software in a separate tutorial. For now, let’s continue discussing the benefits of using flowcharts, which include the following:

  • Enhances communication and collaboration
  • Better visualization
  • Helps developers analyze code and logic
  • Helps debugging
  • Documents processes and program flow

Enhances Communication and Collaboration

Software development is rarely performed in a silo, especially when it comes to commercial applications. Developers need to understand the structure of any programs they are working on, how each module will work, how the different blocks of code will execute, and plan the overall logic and flow of the program. To ensure every feature is accounted for, and to mitigate risks of errors in code or logic, development teams need to layout the software beforehand and determine who will work on which feature, in which order, and how each of those features will work within the program as whole.

This planning results in improved communication and collaboration amongst the team and has the added bonus of relationship building. This enhanced collaboration and communication also helps mitigate risks, increases developer efficiency, and cuts down on waste, as each programmer will have a visual overview of the program and processes they are going to be working on.

Better Visualization

Programmers often use pseudocode to plan projects and layout certain features within a piece of software. For instance, if you wanted to provide a user with the option to Save a file or Save File As, the pseudocode might appear as such:

IF user clicks on File, then Save, save file to current directory under current name.
ELSE IF user clicks on File, then Save As, prompt the user to save the file under a new name and directory.

This is a very simplistic example, but even within such a simple example, multiple processes exist that need to be accounted for. For instance, if user’s choose to “Save As”, we need to account for the ability to create a brand new file, select the type of file, name the file, save the file, and navigate to a different directory (if the user chooses to) before saving the new file. In addition, the current file needs to be closed as well.

All of that may be obvious to a developer – and some of it will be left to platform to handle and will be outside of the developers control – but, again, this is a simple example; multiple that times thousands of lines of pseudocode and you can see how a full-blow program can quickly get out of hand.

Using flowcharts lets developers create a visual map of each step a program or process will take and any possible paths to consider. This visualization of shapes is easier to follow than multiple lines of pseudocode and text.

This is especially true when you begin to map out different modules within a system and create relationships between them.

Helps Developers Analyze Code and Logic

Having a visual overview of a program’s processes, logic, and flow makes it easier to find potential logical errors and issues with conditional statements. Identifying these types of problems prior to the start of the actual coding allows programmers to eliminate errors before they begin, mitigate risks, and save time during the testing and debugging process.

Additionally, analyzing processes and logic can help programmers improve application performance and lead to better reputation with users, who will benefit from software that has fewer errors and performance issues.

Helps Debugging

Debugging is the art of finding errors in code and fixing them, leading to better performing applications, enhancing user experience, and lowering the risk of software crashes. Using the visual cues provided by flowcharts can help programmers identify inconsistencies in logic and decision making. Identifying these problems makes it much easier to locate where issues may be occurring, saving developers time in tracking down bugs.

Helps with Documentation

Documentation is a crucial element of software development that should not be ignored. Providing thorough documentation for end users, stakeholders, and other developers helps enhance user experience and gives other coders another method to understand your code’s intent. Documentation can come in many forms – from actual “how-tos” and technical documents to comments left inside of code and flow charts that show the processes of each portion of your software.

When Should You Use a Flowchart?

There are a number of scenarios in which a developer may wish to use a flowchart. Here are a few:

  • When designing algorithms
  • When planning programming logic
  • When communicating with stakeholders
  • When debugging code
  • When teaching

One situation where a developer will want to use a flowchart or diagram is when designing the logical flow of an algorithm or other complex process. In these instances, flowcharts help break the algorithm down into small pieces, making it easier to visually identify the steps needed to solve a problem or grasp the sequence of events a process needs to take.

The same can be said when planning an application’s programming logic. Flowcharts help visually lay out the flow of the program, let coders organize thoughts, spot issues, and choose the most efficient approach – all before writing a piece of code. Working in this manner reduces code errors, increases productivity, and makes applications more performant. Therefore, programmers are always advised to use flowcharts to plan any piece of software’s logic.

When communicating with stakeholders – especially those that do not have a developer background – it is always helpful to introduce flowcharts as part of the process. Flowcharts and diagrams make it easier for stakeholders to understand how a piece of software works and what steps need to occur throughout the software development process. It also gives stakeholders a chance to provide feedback and explain the software to non-stakeholders or those that are outside of the organization.

As mentioned, when trying to identify errors, issues in performance, or code debugging, it is highly suggested that developers rely on flowcharts to expedite the issue tracking process. Studying process and logic flow from a visual perspective makes the debugging process much easier.

Finally, there are times where a developer will need to teach basic programming concepts to stakeholders, such as investors, sales teams, or marketing departments in order for them to better perform their roles. Flowcharts are an excellent way to explain how a program works from a high-level without digging into the weeds of how code actually works.

Despite flowcharts providing many benefits to the software development process, there are times when a programmer may want to consider not using them. For example, if you are writing a small or very simple program, it may not be necessary to take the time involved to diagram the application.

If you are the only developer working on the project and there are no other stakeholders, creating flowcharts may not make sense either, as you will likely have a high-level of insight into how the code works and will not need to relay that information to others.

What are Flowchart Symbols?

Example of a flowchart with flowchart symbols

Now that we understand the benefits of flowcharts and use cases for creating them, we can look at some of the most common flowchart symbols you can use to map out your software. These flowchart symbols include:

    • Terminal: Used to represent the start or end of a flowchart. Usually represented by am oval shape.
    • Process: Used to represent an action or process in an application. Usually represented by a rectangle.
    • Decision: Used to represent a decision within the program’s flow, from which the code execution may diverge into different branches, based on the result of a condition. Usually represented by a diamond shape that has branches leading to other symbols.
    • Input/Output

: Used to represent an input or output operation. Examples include reading information from a user (input) or printing out text to the user’s screen (output). Usually represented by a parallelogram.

  • Connector: Used to connect the different parts and elements of a flowchart and to continue flow into other sections of the flowchart. Usually represented by a small circle or even a dot.
  • Predefined Process: Used to represent predefined processes and subroutines. Usually represented by a rectangle with two vertical lines on each side.
  • Loop/Termination: Used to represent an iteration, iterator, or loop within the application’s flow. Usually represented by a rectangle with rounded corners.
  • Off-page Connector: Used to connect flowcharts continuing on other pages or sheets. Usually represented by a small circle with a number or letter inside.

This list is not all-encompassing and there are other flowchart and diagramming symbols that exist, depending upon the flowcharting methodology being used. That being said, these are the most common flowchart symbols used by programmers.

Flowchart Tools for Developers

Now that you have a better understanding of flowcharts, their purpose, and the common types of flowchart symbols, check out our highlight of the Best Flowchart Tools for Developers.

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