What is Extreme Programming ? The practice of extreme programming

1. Complete team.

All participants in the XP project (developers, customers, testers, etc.) work together in an open place where they are part of the same team. Large, conspicuous charts and other things showing their progress are randomly hung on the walls of this place.

2. Plan the game.

The plan is continuous and incremental. Every 2 weeks, the developer estimates the cost of the candidate feature for the next 2 weeks, and the customer chooses the feature to implement based on the cost and business value.

3. Customer testing.

As part of the selection of each desired feature, the customer can define an automated acceptance test based on the scripting language to show that the feature works.

4. Simple design.

The team kept the design exactly aligned with the current system functionality. It passes all the tests, doesn't contain any repetitions, expresses everything the writer wants to say, and contains as few ** as possible.

5. Pair programming.

All production software is built by two programmers, sitting side by side on the same machine.

6. Test-driven development.

Writing unit tests is not only a verification act, but also a design act. Again, it's more of an act of writing documents. Writing unit tests avoids a considerable amount of feedback loops, especially when it comes to functional validation.

Programmers work with very short cycles, they add a failed test and then make it pass.

7. Improve the design.

Use refactoring methods to improve your corrupted ** at any time, and keep ** as clean and expressive as possible.

8. Continuous integration.

The team always makes the system fully integrated. When one person checks in, all other owners are responsible.

9. Collective ownership.

Any programmer in pairs can improve any** at any time. No programmer is solely responsible for any particular module or technology, and everyone can be involved in any other aspect of development.

10. Coding standards.

All the **s in the system look as if they were written by a single person.

11. Metaphor.

a global view that ties the entire system together; It is the image of the future of the system, and it is the one that makes the position and appearance of all the individual modules clearly intuitive. If the appearance of the module does not match the whole metaphor, then you know that the module is wrong.

12. Sustainable speed.

The team can only hope to win if it lasts. They work hard at a pace that they can sustain for a long time, they conserve their energy, and they see the event as a marathon run rather than a full-speed sprint.

Extreme programming is a programming idea that aims to improve development efficiency and shorten the development cycle, which is in line with the needs of customers.

Concrete. Flip through the books! Hope it helps.

In addition to technical practice, XP is more important as a management style, or even a business idea.

XP is a practice of agile delivery, which can be used in almost all areas of business, including retail, and if you are interested, you can search for "lean manufacturing" to see how this management style is applied in other areas.

There are four core values in Extreme Programming that we must pay attention to in our development: communication, simplicity, feedback, courage, and a fifth value: modesty.

XP uses "communication, simplicity, feedback, courage and humility" to reduce development pressure and baggage; Whether it is the naming of terms, the content and method of monograph narration, or the process requirements, you can feel a relaxed and happy attitude and atmosphere of active efforts. It is a means of aiding understanding and more easily bringing out the potential of the person. XP has successfully broken the traditional notion that software engineering "must be weighted" to succeed within a certain range with its own practice.

The XP ethos can inspire us to learn and approach rapidly changing, diverse development techniques. The key to successful XP learning is to approach XP with an attitude of "communication, simplicity, feedback, courage and humility"; Feel XP's practical ideas in a relaxed and enjoyable way; After practicing it carefully, through the analysis of real feedback, you can decide the value of XP to yourself; Have the courage to accept it, or improve it.

Extreme Programming is a lightweight, dexterous approach to software development; At the same time, it is also a very rigorous and well-thought-out method. Its foundations and values are communication, simplicity, feedback and courage; That is, any software project can be improved in four ways: enhance communication; Start simple; Seek feedback; Have the courage to seek truth from facts.

XP is a near-spiral development approach that breaks down complex development processes into relatively simple cycles. Through active communication, feedback, and a range of other methods, developers and customers can be very aware of the development progress, changes, problems to be solved, potential difficulties, etc., and adjust the development process in a timely manner according to the actual situation.

Simple and beautiful software designed through software engineering is no more valuable than software that is designed to be complex and difficult to maintain. Is this true? XP believes that this is not the case.

A typical project spends 20 times as much money on people as it does on hardware, which means that a project spends $2 million a year on programmers and only $100,000 on computer equipment. A lot of smart programmers say, "We're so smart and found a way to save 20% on hardware overhead," and then they make the source program big and hard to understand and maintain, and they say:

But we're saving 20 percent or $20,000 a year, which is a big savings." Conversely, if we write our program simple and easily scalable, we will save at least 10% on manpower overhead, a bigger savings, which are some of the things that your customers will definitely notice.

Another issue that is important to customers is bugs. XP doesn't just emphasize testing, it requires the right testing. Testing must be automated in order to provide a safe environment for the program and the customer.

At all stages of coding, we keep adding test cases. When we find a bug, we add new tests, and a tight safety net is created. If the same bug doesn't appear twice, these will definitely catch the user's attention.

Another thing your customers must be aware of: XP developers embrace changing requirements. XP allows us to accept changes in demand.

In general, the customer can only really appreciate the system after it has been developed. XP, on the other hand, shortens the development cycle by reinforcing customer feedback, while gaining enough time to change functionality and gain user buy-in. In XP, your customers should know this explicitly.

Much of the revolution in the XP development process has been in the approach to software development, where quality is more important than people generally think. Just because our customers can't understand our source doesn't mean we don't have to work hard to manage quality.

Everyone in the XP development team follows a unified programming standard, so all the ** looks as if they were written by one person. Because of the unified programming specification, it is easier for each programmer to read what others have written, which is one of the important prerequisites for the realization of collective code ownership.

40-hour week with no overtime.

The XP process uses some figurative metaphors to give everyone a common, concise understanding of the system. XP argues that overtime is not normal because it indicates a problem with the estimation and scheduling of the project's schedule.

metaphor

In order to help everyone have a consistent and clear understanding of the customer requirements to be accomplished and the system features to be developed, the XP development team uses many visual metaphors to describe how the system or functional module works. For example, for a search engine, the metaphor might be "a swarm of spiders, looking around the web for something to catch, and then bringing it back to the nest." ”