Extreme Programming (XP) Overview

Extreme Programming (XP) is an agile approach to software development focused on rapid delivery, collaboration, and skillful development practices. It emphasizes customer satisfaction by responding quickly to changing requirements.

The four core values of XP are communication, simplicity, feedback, and courage.

• Communication: Clear and constant communication between developers and customers is crucial for understanding and addressing needs.
• Simplicity: Prioritize simple, effective designs over complex solutions.
• Feedback: Regular feedback from users and stakeholders helps ensure the software meets requirements.
• Courage: Developers should have the courage to make changes and refactor code to improve quality.

The Planning Game in XP involves collaboration between developers, testers, and customers to estimate the effort required for each feature and prioritize tasks for each release. The team works together to break down features into smaller, manageable tasks, and determine which tasks will be included in the next iteration.

Short, frequent releases in XP allow for faster delivery of working software, improving feedback loops and enabling quicker adjustments. This approach helps maintain the project's momentum and ensures that the team is delivering value to users early and often.

A system metaphor is a shared understanding of the software's architecture and functionality through a simple, relatable analogy. It helps the team communicate effectively, especially during planning and design.

Simple Design in XP prioritizes building the simplest solution that meets current requirements. It emphasizes avoiding unnecessary complexity and focusing on delivering working software first. This approach allows for easier updates and refactoring later.

The practice of refactoring in XP involves continuously improving the codebase without changing its external behavior. Refactoring helps to simplify and clean up the code, making it easier to understand and maintain, and reduces technical debt.

Pair programming in XP involves two developers working together, side by side, on the same code. One person drives, writing the code, while the other acts as a navigator, reviewing the code and suggesting improvements. This practice enhances code quality and helps to share knowledge within the team.

XP (Extreme Programming) emphasizes close collaboration between developers, customers, and managers in a shared project environment. This team-oriented approach aims for rapid software delivery with high business value.

XP differentiates itself by minimizing documentation beyond program code and tests. While not prohibiting other documents, it prioritizes immediate development over extensive upfront planning.

Unlike other evolutionary methods, XP relies heavily on oral communication for requirements and design. Instead of detailed written plans, features are discussed face-to-face between developers and customers.

XP values simplicity, prioritizing clean and straightforward design over complex solutions. This approach aims for maintainability and ease of understanding.

XP emphasizes continuous feedback through testing. Testing begins from day one, allowing for early detection and correction of issues, leading to a more robust software product.

XP advocates for delivering working software to customers as early as possible. This allows for real-world feedback and iterative improvement based on user needs.

XP values courage to embrace change and adapt to evolving requirements. The process is designed to be flexible and responsive to new information.

XP practices are likened to a jigsaw puzzle, where individual practices seem small, but when combined, they create a complete and effective development methodology.

A role that collaborates with customers to develop tests for a software application.

A role that helps facilitate the project's progress and ensures adherence to processes.

A role responsible for collecting project data, analyzing progress, and providing insights on estimations.

A role that provides technical expertise and guidance to the team.

A practice where the entire development team, including programmers and customers, works in a shared space for enhanced collaboration.

A testing practice that involves defining and automating acceptance criteria for software functionalities, often created in collaboration with customers.

A testing practice where programmers write unit tests before writing the corresponding code, fostering a test-first mindset.

In XP, customers, especially when not physically present, should be easily reachable for quick feedback and adjustments.

XP prioritizes embracing changes in requirements, design, and code to adapt quickly and effectively.

In XP, team members voluntarily choose tasks during planning, leading to higher commitment and ownership.

XP emphasizes minimal upfront design, favouring short bursts of design before starting to code.

XP promotes minimal documentation, focusing on getting to code quickly. Verbal communication and short notes are prioritized.

XP advocates for measuring progress and quality daily using simple metrics like completed tasks and successful test runs.

XP uses visible wall graphs to display progress and quality metrics, making them readily accessible to everyone.

A designated person tracks progress by regularly checking with developers, using in-person conversation instead of email, reflecting the focus on human interaction in XP.

A continuous process of improving the code without changing its functionality, done frequently and in small steps. It involves cleaning up the code and design to make it simpler and easier to understand.

The entire team owns all the code, any programmer can improve any part of it. It removes individual code ownership bottlenecks and encourages collective responsibility.

A process where all code changes are automatically integrated and tested on a separate build machine. It ensures that every change is tested and that the whole system remains functional.

The practice of using metaphors to explain the overall system or its subsystems. This helps in communication and makes it easier to understand the system's design.

Small handwritten cards used to describe the features or functionalities that need to be developed. They serve as a way to break down user stories into smaller tasks.

A set of rules for how the code should be written. This ensures consistency and readability across the entire codebase.

The practice of working in pairs on the same piece of code. This helps in learning from each other, identifying errors, and improving code quality.

The principle of avoiding overtime work. It encourages healthy work-life balance and prevents compromises on code quality.

A dedicated acceptance tester works with the customer to translate their acceptance criteria into executable tests. Smaller projects can have the tester perform this role part-time.

A key person (Big Boss) responsible for project goals and milestones should be aligned with the on-site customer to ensure consistent vision.

The customer writing acceptance tests should not also be responsible for reviewing their execution. This creates a conflict of interest.

XP iterations should be short, ideally lasting 1-3 weeks. Longer iterations make it more difficult to adapt quickly to changing requirements.

Iterations should have a fixed time frame. When facing challenges, the focus should be on simplifying goals or removing features, not extending the iteration time.

Each iteration should conclude with an integrated and tested software baseline. This ensures the team has a working, stable version of the software at the end of each iteration.

The baselined software at the end of an iteration is an internal release, not a final production release. Several iterations are typically needed before a production release.

Predictive planning, where the entire project is meticulously planned upfront, is not an XP practice. XP embraces adaptive planning, where iterations are planned based on feedback and experience.