Code reuse is a method for designing computers and other systems, by reusing code that already exists. A system should be partially or completely composed of parts of components written earlier and/or parts of another system. Code reuse is the primary method that is used to reduce labor costs in the development of complex software systems.
Talks about “code reuse” are very popular among programmers and mostly they talk about it positively. They like to think that the designs they have designed are “universal” and “suitable for other projects.” But is it true?

Code Reuse: Is it worth it?

Code reuse is really useful if you are creating something that you plan to use as a library for multiple projects. This method is saving time and resources and reducing reduction by using resources already created. The key idea in code reuse is that parts of a computer program written at one time can be used in the construction of other programs written at a later time.
Some so-called “reuse” codes simply involve copying some or all of the codes from an existing program to a new one. Although organizations can use this approach, they may face many of the same problems associated with license codes caused by shortening and programming.

Types of code reuse

Many researchers have worked to make code reuse method faster and easier. Code reuse can be further classified:
• Internal reuse – the organization reuses its own components. This may be a good business decision, as the organization may want to control a component that is critical to the project.
• External reuse – the organization can license a third-party component. Licensing a third-party component usually costs 1-20 percent of the development cost within the company. The team should also consider the time to find, study, and integrate the component.
For example, one of the biggest template markets is Here people can buy themes, make text image edits and publish the site as they would build it. Although, it’s not a bad approach if you are a small business and need a quick solution. The big question is – what if you want to build a Facebook-like site, can you find a template and re-use it? Even if you can, the answer is no. Because it’s hard to adapt to someone else code base also very hard to update, and probably easier to start a new project from scratch.

Advantages and disadvantages of the code reuse method

Let’s consider the advantages and disadvantages of code reuse. Our goal is to reduce costs, increase reliability, and improve consistency.
• Cost – the cost of using existing software is usually less than the cost of developing an equivalent product. The cost of purchasing software products is less than the cost of using open-source projects. Although changing the existing code is more difficult than writing a new one).
• Reliability – two situations are simple to overlook when rewriting code. The first is some functional code added by the original author. The second is a new code added to the source code after they detected a defect in the test. Using proven code is usually more reliable than new code.
• Consistency – the external interface provided by the system must be consistent: write a new code that can be consistent with other parts of the system function.
We also should think about the size of the project. For example, below are the advantages and disadvantages of code reuse for a small website.
• Quick to market.
• Cheap price (usually that is a small fee or 10-30 USD per month).
• Often includes updates.
• Your final product is not unique (feels like it is a template cheap solution).
• Often not very much customizable.
• You still need to hire a programmer or a freelancer programmer to implement the project.

For complex and large applications, the situation with code reuse is different

• If a solution 100% matches your needs and has qualified support and pricing, it makes sense to use it.
• Still cost significantly (a usually a monthly paid plan you going to pay forever).
• You are going to need an in-house team to manage operations and development/improvements.
• That is very difficult to work with someone else code base, sometimes even impossible as it can be very messy.

Risks of code reuse

Code reuse comes with certain risks. There are situations when it may simply be impossible. One problem with justifying investments is that some managers do not give time to master the old code. Another potential risk is a lack of understanding of the scope and components of the code. Another potential risk is the inability to perform an analysis.
The desire to understand the complete code can be an overwhelming task, so it is important to divide the code into components and highlight the key parts for reuse. Take the time to identify the code components that should be reused. Sometimes, it may be necessary to fully document the code. For example, according to regulatory requirements, but attempts to reuse and document the entire code are usually not effective. The primary goal should be to identify code snippets for documentation and reuse.

Code reuse: four key aspects of success

The main key aspects of successful code reuse are:
1. Understanding the architecture of the original code to identify components, boundaries, and interfaces.
2. Determination of the potential for reuse.
3. Evaluation of the time spent on reuse compared to the re-creation of components.
4. Deciding on each component: what to reuse and how (unchanged, with minor or significant changes).


The most important thing is that it’s very easy to think ”hmmm this solution matches 80% of what I need.” Surely, it’s cheaper to just add additional features. Still, we don’t recommend you to do that. It is harder to adjust the existing structure and solution, change the design and do everything under someone else code.
Code reuse is possible as long as you are happy with a copycat or completely the same solution. The minute you customize the existing code, it becomes hard to keep the structure in the correct way. Code reuse is not an option for you if you want to have excellent performance. Although custom development is expensive, it brings quality if you choose the right developers.