Extreme programming (XP) is one of the most important software development methodology of Agile models. According to the Alliance definition, “Extreme Programming (XP) is an agile software development framework that aims to produce higher quality software and higher quality of life for the development team.
Furthermore, XP is the most specific of the agile frameworks regarding appropriate engineering practices for software development.” In simple words, Extreme programming is about good practices taken to an extreme.
Extreme programming is based upon a set of principles, practices, which aims to allow small to midsize teams to develop high-quality software while adapting to changing, evolving requirements. XP differs from the other agile methodologies since it emphasizes the technical aspects of software development. XP is specific in how software developers perform because the best engineering practices enables teams to produce high-quality code at a sustainable rate.
Extreme Programming (XP) is a software engineering process, first introduced by Kent Beck in 1996. In the mid- 1980s, Kent Beck and Ward Cunningham started Pair Programming at Tektronix. One the main issue arises in the conventional software development procedures was not being cost-effective for companies. It resulted in a huge cost due to constant changing requirements and modifying those new requirements, and that was the period when Extreme Programming came into picture. In 1999, Kent published his book, ‘Extreme Programming Explained’.
Importance of Extreme programming-
- Extreme Programming is beneficial in cases of changing requirements, which introduces barriers where new requirements can be modified.
- Extreme programming encourages developers to avoid duplication.
- Defined Coding standards to help teams work hand in hand.
- Using System metaphor technique to further improve understanding of the source code.
Core Principles of Extreme Programming
1. Embracing change and adaptability
Making gradual, minor adjustments is preferable to having to deal with everything at once. When a client wants to modify the product, Extreme programming assists programmers to plan the implementation of new improvements.The optimal plan of action is the one that addresses your most pressing issue while maintaining the greatest number of possibilities.
2. Continuous feedback and communication
This principle of the XP model gains feedback to understand the exact customer needs and respond to it quickly. Team members deliver products frequently, get feedback about it, and improve the products according to the new requirements. Communication is important to work together effectively and share knowledge.
3. Simplicity and minimalism in design
Simple and easy-to-read code saves time, enhances product value and produces effective code that works properly. The main principle of the XP model is to develop a basic system that functions efficiently now, rather than trying to build something complex. It focuses on minimalistic design that contains only some specific features that are immediately needed, rather than engaging time in future requirements. An excellent design removes all complex dependencies within a system.
4. Test-driven development and automated testing
XP teams use test-driven development (TDD), which involves creating an automated unit test before writing the actual code. Software engineers thereby focus on writing code to achieve the required function so that each and every piece of code must pass the test.
- TDD allows programmers to develop reliable software by utilizing immediate feedback.
- TDD fosters a pleasant, cyclical rhythm where the next step is always obvious and enables programmers to have confidence in the code they produce.
- It ensures 100% code coverage, encouraging code refactoring and high-quality code.
5. Pair programming and collective code ownership
XP encourages pair programming which promotes knowledge sharing, minimizes errors and improves code quality. In this type, the first developer focuses on writing the code, while the other one reviews code, suggests improvements, and fixes errors. Such teamwork results in high-quality software.
There is no exclusive ownership of code in XP. The codebase is instead the responsibility of the entire team. This principle ensures that every team member has a sense of responsibility and ownership for the code.
Key Practices in Extreme Programming
1. Planning and prioritizing user stories
XP follows a planning game, where the development team and the client customer collaborate to prioritize and schedule development activities. While planning the stages of Extreme programming, you determine if the project is feasible and the best fit for XP. You need to prioritize user stories to find if they match the simplicity value and allow you to ensure the availability of the user for the process. If the user story is more complex, or it’s created by an anonymous customer, it’s possible that the user stories won’t work for XP.
2. Frequent releases and iterations
This practice suggests quick release of the minimum viable product and iteratively developing the product by making minor updates. With small frequent releases developers can detect bugs early, receive feedback, and monitor how the product functions in production. One of the methods of frequent releases and iterations is through continuous integration practice.
3. Continuous integration and deployment
In XP, developers merge their code into a shared repository several times a day. The shared code helps collaboration among developers on the used and unused codes and detect integration problems early on in the development process. XP teams take iterative development to a new level since they update code multiple times a day, which is also called continuous delivery. This way, they can precisely determine what exact functionality they need to develop.
4. Refactoring and code improvement
XP encourages refactoring and other techniques of code improvement, to deliver reliable software in every short iteration. Refactoring is all about restructuring existing code to make it more organized, efficient and easy to understand. Refactoring reduces duplication, gets rid of pointless functions, improves code coherence, and decouples pieces all at once.
5. On-site customer involvement
Extreme programming ensures full customer involvement in development. Customer presence is necessary all the time to respond to team queries, set priorities, provide feedback, and settle disagreements.
Benefits and Challenges of Extreme Programming
1. Improved software quality and reliability
Extreme Programming procedures saves costs and time required to complete the project. XP eliminates unnecessary tasks to reduce the costs and allows developers to focus on coding to produce robust and quality software.
2. Enhanced team collaboration and communication
Team members work together on everything from requirements to code which results in enhanced team collaboration and communication. Developers work in pair programming principles where they share ideas, create software and support each other throughout the entire project. Hence, there is increased employee engagement and satisfaction.
3. Increased customer satisfaction and engagement
ХР is customized to meet all customer’s requirements and that is why the end product meets all the demands. XP strongly focuses on customer engagement and requires the availability of the client to obtain feedback or answer queries so the project can be implemented in a more efficient manner.
Extrеmе Programming offеrs a uniquе approach to software engineering, еmphasizing adaptability, collaboration, and continuous improvеmеnt. By еmbracing its corе principles and implementing kеy practicеs, dеvеlopmеnt teams can enhance their productivity, dеlivеr high-quality softwarе, and fostеr a positivе working environment.
In largе-scalе projеcts, extreme programming allows flexibility to make modifications across thе wholе softwarе development lifecycle. High-quality softwarе is producеd using XP’s distinctive dеvеlopmеnt approach, which incorporates usеr fееdback and aggrеssivе, collaborativе programming.