XP

What is the full name for ‘XP’? 

Extreme Programming

Who developed Extreme Programming?

Kent Beck

Where was it first used?

On the Crysler Comprehensive Compensation (C3) program.

Who was brought in to improve the system?

Ron Jeffries

When was Extreme Programming developed?

March 6, 1996

Main objective for Extreme Programming

Improve software quality and responsiveness to customer needs.

Extreme Programming has a relation to what?

Agile methodology

5 principles of XP

1. Communication

2. Simplicity

3. Feedback

4. Courage

5. Respect

These 5 principles align with what?

Agile values and principles

First 6 core ‘XP’ Principles

1. The Planning Game

2. Customer Tests

3. Small Releases

4. Simple Design

5. Pair Programming

6. Test-Driven Development

Last 6 core ‘XP’ Principles

1. Refactoring

2. Collective Ownership

3. Continuous Integration

4. Sustainable Pace

5. Metaphor

6. Coding Standards

The Planning Game

• Collaboration between developers and customers.

• Determining goals and timelines.

• Dynamic adjustment as the project evolves.

Customer Tests

• Developers acceptance tests to match user stories.

• Ensuring delivered features meet customer needs.

Small Releases

• Delivering software incrementally.

• Early and frequent releases to gain customer feedback.

Simple Design

• Focusing on simplicity and avoiding overcomplication.

• Delivering just what is necessary.

Pair Programming

• Two developers working together at one workstation

• Benefits of collaboration include code quality and knowledge sharing.

Test-Driven Development

• Writing tests before coding.

• Ensuring code quality with automated tests.

Refactoring

• Cleaning up code to improve design and maintainability.

• Removing duplication and enhancing code readability.

Collective Ownership

• Encouraging any team member to modify any part of the code.

• Promotes responsibility and shared accountability.

Continuous Integration

• Frequently integrating code into a shared repository.

• Reduces integration problems and ensures consistent quality.

Sustainable Pace

• Avoiding burnout by maintaining a consistent and reasonable work pace.

• Establishing achievable deadlines based on team capacity.

Metaphor

• Using a shared metaphor to simplify the system’s design and communication.

• Example: “The system is like a library.”

Coding Standards

• Enforcing a consistent coding style across the team.

• Ensures readability and maintainability of code.

What is XP?

An agile software development framework that aims to produce higher-quality software and a higher quality of life for development team.

‘XP’ is the most specific of what?

The agile frameworks in terms of engineering practices.

When is Extreme Programming applicable and name some of the general characteristics where it is appropriate?

• When you have dynamically changing software requirements

• Fixed-time projects using new technology

• A small co-located extended development team.

• The technology allows automated unit and functional tests.

Why might ‘XP‘ not be fully suitable in some situations?

• ‘XP’ is quite specific when it is a set of engineering principles.

• Many contexts may not allow full ‘XP’ usage, but you can still adopt as many of the practices as your context allows.

Communication

This is key because software development is a team sport and it emphasizes face2face discussion to transfer knowledge quickly among team members.

Simplicity

• Means “What is the simplest thing that will work?”

• The aim is to avoid waste, design only what is absolutely necessary, keep system design as simple as possible so it’s easier to maintain, support, revise, and avoiding trying to predict the future.

Feedback

• Through constant feedback about previous efforts, teams can identify areas for improvement and revise practices and design.

• Feedback supports simple design because you build, get feedback, and adjust going forward.

Courage

• Defined as “effective action in the face of fear.”

• Needed in ‘XP‘ to raise organizational issues, stop doing what doesn’t work, and try something else, accept and act on feedback even when difficult.

Respect

• Team members must respect each other so communication, feedback, and work together on simple designs and solutions can happen.

• Required to create a healthy team environment

7 refined/modern practices

1. Sit together

2. Whole team

3. Informative Workspace

4. Energized Work

5. Team-Minute Build

6. Ten-First Programming

7. Incremental Design

Typical roles in an ‘XP‘ team

1. Customer

2. Developer

3. Tracker

4. Coach

Customer

Responsible for business decisions (what the system should do, acceptance criteria, how much to spend, what to do next) and is actively engaged.

Developer

Everyone (besides the customer and optional roles) is considered a developer; responsible for realizing stories.

Tracker

• Optional

• A developer may take this part‑time to track metrics when the team sees value.

Coach

• Optional

• Someone experienced in XP who helps mentor the team in XP practices and self‑discipline.

What is the lifecycle of an ‘XP‘ project in terms of cycles?

• First

• Release/Quarterly Cycle

• Weekly Cycle

First

• Customers define stories (feature descriptions).

• The team estimates size and value so the customer can prioritize.

• Spikes (time‑boxed research) may be used for unclear stories.

Release/Quarterly

• The team and customer make a release plan for quarter / release

• Stories may change.

Weekly Cycle

• At start of each week, team + customer decide which stories will be delivered that week.

• Break into tasks.

• End of the week, team + customer progress and decide to continue or stop.

What is the primary contribution of ‘XP’ to software development?

The interdependent collection of engineering practices that help teams be more effective and produce higher-quality code.

A primary contribution of ‘XP‘ to software development is also what?

The focus on practice excellence: the method prescribes a small number of essential practices and encourages teams to perform them as well as possible (almost to the “extreme”).

What does “extreme” mean in Extreme Programming?

• Taking sound engineering practices and applying them in an intense, disciplined way

• Pushing best practices to their limits so the benefits are maximized.