How to write maintainable software


It is critical for businesses to have maintainable software because requirements can change over time, and the software must be able to meet those requirements. Software that can meet the changing requirements of the market will always remain trendy and in use, and if not, then it will become obsolete. This is why businesses strive to make maintainable software. By maintainable software, we mean software that is easy to understand, modify, and extend. 

Importance of having maintainable code

Here are some of the noted reasons for having maintainable code:

1. Reduce software development costs

You might be amazed to note that software maintenance takes up a huge chunk of the funds allocated for software development. This is often because many developers do not realise the importance of writing maintainable code. Often they write large codes, and the developers who come after that will have to wrestle with the codes because they have become unmanageable. 

2. Better collaboration among team members

When the codes are maintainable, there is better collaboration among team members. They will be able to work faster, completing their tasks more successfully. 

3. Easy scalability

When the codes are maintainable, it helps in enhanced scalability. you can easily scale your app when the demand gets higher. With the bad quality codes, scalability might not be an option since the software will have to be thrown out. 

How do you measure code quality?

Measuring high-quality code could be tough for any software sizing algorithm. This is because defining the right code quality could become a challenge. The best way to measure the code quality is by considering the qualitative approach. This would help developers to follow the rules for writing quality code. It would also help to measure the code quality and analyse their performance in the market. Here are some tips to measure the code through the qualitative approach:

  • Checking the code’s reliability
  • Assessing the code’s portability
  • Determine the complexity levels of the code
  • Checking the code’s reusability level
  • Measure the program’s testability level
  • Using the latest code-checking tools

A couple of code metrics you can use 

There are some code metrics that you can use to determine their code quality. Check them out:

1. Defect metrics

Through the Defect metrics, you will be able to gauge the number of defects in the code and their severity. The programmers and developers will identify the defects, the stage at which the defect is, the source or originating point, and the density of the defects. 

2. Halstead’s complexity metrics

Proposed by Maurice Halstead, this particular metric evaluates the complexity of the software program. It will analyse the source code testing time, size, difficulty, errors, code testing time, and calculated program length.

Some best practices for writing clean and maintainable code

Given below are some simple guidelines and principles you can use for writing high-quality, easy-to-maintain code. Following these principles would help with readability, efficiency, and of course, maintainability of the code. Following these guidelines would help developers save time and resources in the future when they want to scale or modify. 

Self-explanatory names

Your classes, methods, and variables must have easily understandable names. The name must be just enough for the developers to understand, so there would be no ambiguity or confusion. Your code will be read by other developers easily, and it saves them a lot of time, even reducing the likelihood of errors or bugs. 

How to write self-explanatory names

It is simple. Just:

  • Write descriptive names that describe what the code does
  • Avoid abbreviations because who knows, you might even forget what that means
  • Be consistent with the naming
  • Avoid using reserved keywords like “if”, “else”, “for”, etc. 
  • Follow the system of writing verbs for functions and nouns for classes and variables.

Follow coding standards

With coding standards, your codes will have a uniform appearance that, even though written by different engineers, will look the same. This would of course facilitate the readability, and maintainability while reducing the complexity of the codes. 

How to follow coding standards

When there are established coding standards, you can have a strong code foundation. So here are some quick guidelines:

  • Breaking the codes into small, modular functions and classes
  • Having a consistent coding style, complete with naming conventions, line lengths, and indentation.
  • Adding comments and documentation so the developers will understand how the software parts work.

The KISS Method still applies

Simple codes are easily maintainable, so KISS (Keep it simple, stupid!). So let that be the developer’s guiding principle. Make sure to write codes with each module or class having a single responsibility. More than that could be confusing. 

How to maintain the KISS methods

There are simple tips that will make the codes simple. Check them out:

Plan the code

  • Write the code for humans
  • Use meaningful names and simple algorithms
  • Follow coding standards
  • Use simple algorithms so the codes are easy to understand
  • Avoid premature optimisation by focussing on writing clean, maintainable codes first
  • Refractor regularly to keep it clean and simple
  • Test regularly

Modular codes are easily replaceable 

Modular codes can be reused so developers must make sure to write codes that can be broken down into small, manageable components. Even if you are not the developer that will be managing the codes later, the developer that follows can save time by understanding them and reusing them in the different parts of the application. So write codes with single tasks so they can be easily maintained. 

How to write modular codes

  • By using classes and objects the codes can be broken down into smaller components
  • Break the codes into smaller functions with single functions
  • Avoid reinventing the wheel by going for libraries and frameworks that reuse codes
  • Dependency injections help inject dependencies into code to make them easily testable and maintainable

Version control systems like Git 

With a version control system like Git, it would be easier to collaborate with your team and keep track of the changes that are being made. 

How to write using version control systems

There are some ways in which you can write version control systems. Check them out:

  • Choosing the right version control system like Mercurial, SVN, Git, etc.
  • Use branches because they can separate the different versions of the code, making it easier to work on the different features without them interfering with each other
  • Using pull requests can help review code changes, work with other developers, and make changes so they can be merged with the codebase 
  • Use tags to mark the important milestones so you can track the changes easily. 


These are some of how you can write maintainable software. And once the software is ready, don’t forget the testing and test automation part because they are so important, not only in the development phase but in maintaining code quality as well. Some of the most common testing types are Unit Testing, Integration Testing, Regression Testing and Test Automation:

Interesting Links:

More information on Software Maintainability

Check what exactly is Maintainability in Software Development

Pictures: Canva

The author: Sascha Thattil works at which is a part of the YUHIRO Group. YUHIRO is a German-Indian enterprise which provides programmers to IT companies, agencies and IT department.

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