Extreme Programming (XP) vs Scrum

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. XP is the most specific of the agile frameworks regarding appropriate engineering practices for software development.

Scrum is a framework within which people can address complex adaptive problems, while productively and creatively delivering products of the highest possible value. Scrum itself is a simple framework for effective team collaboration on complex products.

Scrum and XP are both Agile approaches that share the common concepts of iterative development, working software, release and iteration planning, daily meetings, retrospective, all elements of an Agile process. Both approach are aligned each other that sometimes is difficult to distinguish between a team who is adopting XP while another team who is doing Scrum.

There are however some differences, some of them very subtle, and particularly in the following 4 aspects:

1. Iteration length

Scrum

• Typically from two weeks to one month long.

XP

• Typically one or two weeks long.

2. Whether requirements are allowed to be modified in an iteration

Scrum

• Do not allow changes into their sprints.
• Once the sprint planning meeting is completed and a commitment made to deliver a set of product backlog items, that set of items remains unchanged through the end of the sprint.

XP

• Much more amenable to change within their iterations.
• As long as the team hasn’t started work on a particular feature, a new feature of equivalent size can be swapped into the XP team’s iteration in exchange for the un-started feature.

3. Whether User Story is implemented strictly according to priority in iterations.

XP

• Work in a strict priority order.
• Features to be developed are prioritized by the customer (Scrum’s Product Owner) and the team is required to work on them in that order.

Scrum

• Scrum product owner prioritizes the product backlog but the team determines the sequence in which they will develop the backlog items.
• A Scrum team will very likely choose to work on the second most important.

4. Whether to adopt strict engineering methods to ensure progress or quality in the process of software implementation

Scrum

• Doesn’t prescribe any engineering practices;

XP

• XP does.
• For example: TDD, pair programming, simple design, refactoring…

 We can summarize the differences between XP and Scrum as follows:

Aspects	Practices	XP	Scrum
Iteration Length	Whether to allow modification of requirements	1-2 weeks	2-4 weeks
Handle Changes with an Iteration	Whether the demand is strictly in accordance with the priority	It can be replaced with other requirements when a need is not implemented, but the implementation time is equal.	Scrum is not allowed to do this. Once the iteration is completed, no changes are allowed, and Scrum Master is strictly checked.
Priority of Features	Whether the demand is strictly in accordance with the priority	Yes	No need to
Engineering Practices	Whether to adopt strict engineering methods to ensure progress or quality	Very strict	Require developers to be conscious

Therefore, we believes that XP’s approach is acceptable, but it brings Agile into a confusing paradox, because the idea of XP, combined with agile mode, conveys to the team the message that “you are a fully self-managed organization, but you have to implement TDD, pair programming, etc.”

It is not difficult to find that the four distinctions are quite obvious:

• In Scrum, it emphasizes self-organization
• In XP, it emphasizes strong engineering practice constraints.

Conclusion

Scrum is a framework for product development, which is a container where you can add other practices. XP is one of those practices that you can do within Scrum framework. There are no reasons why a team should choose between Scrum and XP. XP rules and practices are not easy and the majority of XP rules are non-negotiable. Adding XP into Scrum could be a natural path for teams starting out with Scrum and striving to be a professional Scrum Team.

About Visual Paradigm

Visual Paradigm help organizations stay competitive and responsive to change faster and better in today’s fast changing environment. Our award-winning products are trusted by over 320,000 users in companies ranging from small business, consultants, to blue chip organizations, universities and government units across the globe. It enables organizations to improve business and IT agility and foster innovation through popular open standards and process frameworks.Visual Paradigm, a killer Agile feature in 2018, introduced Scrum Process Canvas for automating the way a Scrum team to create, manage and deploy software application that empowers the team to continuously improve their performance at unprecedented speed and scale. Manage the Entire Scrum Process in One Page Automate the Scrum Framework in a fun and enjoyable dashboard with eye-catching updated status. Manage Backlog, Multiple Sprints of different Scrum Roles with a single-page visually executable canvas Allow instantly access, review and generate scrum artifacts and related documents to be archived in the Shared Cabinet Automate the Scrum events and related activities with self-explanatory instructions, samples and required document templates.