Are you familiar with eXtreme Programming, its principles and benefits?
Have you ever heard of eXtreme Programming (XP)? What do you know about this software development method?
Originating in the agile world, this methodology came to prominence at the turn of the 1990s and 2000s. But what exactly does it consist of?
In this article, we focus on the principles that govern it, the advantages and disadvantages it offers and the techniques you need to follow to achieve it.
What is eXtreme Programming?
Definition
eXtreme Programming isan agile methodology and its most advanced implementation in software development, hence the term "extreme".
Based on a customer-centric approach, this method offers a framework that aims to produce simple but high-quality code for the entire team involved in the project.
Developed by Kent Beck, an American computer scientist also known for his concept of Test-Driven Development, eXtreme Programming has played an important role in the success of agile methods.
eXtreme Programming vs Scrum
The Scrum method is also part of the agile family. In fact, the two can be combined, as they are complementary:
- the Scrum method is a frameworkfor project management and organisation;
- eXtreme Programming focuses on development activities, in particular the systematisation of automated testing.
What are the characteristics of eXtreme Programming?
The 5 key values
Initially designed for the IT industry, eXtreme Programming is now very popular throughout the world, as it is functional for all types of projects, of all sizes and in all sectors.
It is even said to work best in small to medium-sized teams of no more than twenty or so people.
The main characteristics of eXtreme Programming are those of the agile universe: responsiveness to change, flexibility, collaboration, quality of work, quality of testing, etc.
☝️ The difference lies in the fact that these features are taken to extremes.
Let's take a look at its fundamental values:
- Communication: it is essential that every member of the team communicates on a daily basis both internally and with the customer. Contact is an essential means of solving problems.
- Simplicity: often, the simplest way to achieve a result is also the most effective. So it's important to keep things simple and to the point. As a result, the development team should focus exclusively on the tasks that are strictly necessary. Improvements can be made later.
- Feedback: the exchange of information between the project team and the customer is essential. Any changes to the project must be communicated to the customer as quickly and frequently as possible. Any requests for changes must be considered immediately.
- Respect: respect for the work of the people involved is a sine qua non. Management, the project team and the customer must respect each other.
- Courage: change requires courage to get out of a complex situation, whether it's learning to master a new technique, restarting an iteration that hasn't been validated or reorganising a project.
The 12 fundamental rules
In practical terms, the 5 key values outlined above giverise to 12 fundamental rules. These can be grouped into 4 areas.
🔁 Detailed feedback
- Pair programming: this mechanism aims to control the quality of the work. You work in pairs: while one colleague writes the code, the other checks it. To work together on a shared workstation, it is very important to ensure that the pair have a similar level of experience.
- Planning poker: planning is done in collaboration with the customer. The customer expresses the functionality he wants to benefit from. The team assesses the time needed to implement it. Finally, the various tasks are prioritised. This meeting generally takes place on a weekly basis.
- Test-driven development: the test environment (both unit and acceptance) is written before development of the functional part and creation of the source code. This technique enables you to identify any errors in advance.
- On-site customer: ideally, at least one customer representative should be an integral part of the team, so as to have an overall view of the desired result and be able to answer any questions.
🧘♂️ Well-being of programmers
- Sustainable rhythm: overtime is prohibited. If overtime is necessary, the upstream programming must be reviewed. A tired employee works poorly and makes more mistakes. It's a good idea never to exceed 40 hours a week!
∞ Continuous process
- Refactoring (or design improvement): the project is constantly being improved. The aim is to work on solid foundations and have optimal working conditions. The code therefore constantly eliminates repetitions and unnecessary elements.
- Small releases: these should be as frequent as possible, to give the customer the opportunity to voice criticisms and suggestions on an ongoing basis. In this way, errors are detected and corrected more quickly.
- Continuous integration: as soon as a task is completed, it is immediately integrated into the product. This avoids the extra work required to integrate all the elements before final delivery. Testing facilitates this integration: when all the tests are positive, the iteration is complete.
💡 Common (or shared) understanding
- Collective ownership of the code: responsibility for the project is collective. This means that each member can intervene in all sections of the project, including those on which they have not worked. The aim? Maximum efficiency and speed.
- Coding standards: as they all work together, it is essential to facilitate everyone's work by using the same terms, the same style, and well-defined modes of communication.
- Simple design: this allows you to have code that everyone can understand and avoid duplication. The focus is on the customer's needs.
- System Metaphor : metaphors are used to describe the project as simply as possible. The aim is for new employees to be able to understand and integrate the project quickly.
Advantages and disadvantages of eXtreme Programming
If all the conditions are met, eXtreme Programming can deliver surprising results.
✚ Here are some highlights:
- clean, linear code,
- stable software thanks to continuous iterative development,
- the ability to make constant improvements.
⊖ Weaknesses include:
- a higher average budget,
- the need for strong customer involvement,
- a high need for self-discipline and planning.
eXtreme Programming: the method that gets straight to the point
With this method, managers, developers and customers work together. This collaborative approach pushes simplicity and responsiveness to the maximum and ensures continuous version control.
In practice, it's a complex method to implement because it requires a great deal of self-discipline and good internal communication. However, if the conditions are right, this method can lead to excellent results.
Have you ever seen this agile method? What are your impressions?
Article translated from French