Agile methodology has been a widely accepted methodology in contemporary software cultures. With its adaptive and highly productive results, it is a highly favored framework among software developers.
In this article we are going to look at two of the most widely used agile methodologies, which are Extreme Programming (XP) and Scrum. Though they follow most of the same iterations, they differ in certain elements. Let us begin with Extreme Programming.
Extreme Programming (XP)
XP is an agile software development methodology. Like most methodologies, it is high on adaptability and responsiveness. One of the most noticeable factors in XP is that changes are considers absolutely normal throughout the process and are incorporated very frequently throughout the process. In XP, you can see an increased number of releases; which is done to enhance productivity and to assimilate customer requirements from time to time.
The process of developing a software using XP methodology includes- release planning phase, iterations, and user acceptance testing. However, iterations are encouraged throughout the process.
User stories is a unique concept attached to XP. A designated user writes stories about how their software needs to fulfill certain demands. Developers use these stories to define user acceptance tests. The user stories also help the team to estimate the time and resources required to build the release. The user stories are usually broken down into stacks of related functionality. These stacks or iterations, are further prioritized by the client so that most essential tasks are established first.
At the end of each iteration, the user performs a user acceptance test against the user stories. This test determines the completion of the particular iteration, and additionally points out bugs, if there are any.
The XP methodology expects development teams to integrate changes to the development baseline at least once a day. This concept is popularly known as Continuous Integration. All production code is pair programmed; i.e., a pair of programmers integrates the code at any given time. This methodology believes that a pair of programmers writing the code satisfies user stories with higher quality (though the time taken to do so, isn’t altered drastically). XP gives high importance to the simplicity of a product design. Though simplicity is defined as subjective, it is faster to achieve a simpler design as opposed to a seemingly complex one.
Like XP, Scrum is another widely used agile software development methodology. According to Wikipedia it is an “iterative and incremental agile software development methodology for managing product development”. Unlike XP, Scrum methodology includes both managerial and developmental processes.
The Scrum approach assumes that a need cannot be completely defined from the very beginning of the process, hence the team is encouraged to deliver according to emerging requirements throughout the process.
The process starts with the creation of a backlog. This backlog is then divided into sprints where the estimated time for each sprint is targeted. Sprints are nothing but iterations, which generally last around 2-4 weeks long. The scrum team however, doesn’t allow changes to these sprints. Once a sprint plan is in place and the plan is finalized, it remains unchanged till the end of the sprint. At the end of each sprint, the team aims to achieve a potentially shippable product with little or no changes at all.
The team members regularly keep each other posted on questions like what they did yesterday, what they are going to do today and if there are any impediments that need to be addressed immediately. This is called a daily scrum. At the end of each sprint, teams holds sprint reviews and sprint retrospectives.
The scrum team comprises of as scrum master, developers and a product owner. The scrum master conducts the daily scrums and ensures that whatever impediments are faced by the team are taken care of, to ensure smooth functioning of the process. Products owner is someone who represents the client onboard. They function like a product manager.
The key elements to this process are the product backlogs, sprint backlogs and burn down charts.
Product backlog is like a wish list of features that the product owner would like to see in the final products. After careful selection, a sprint backlog is created. This backlog consists of some select elements from the product backlog, especially the ones that the team wants to address first. As one sprint backlog is materialized at the end of a sprint cycle, the team moves to another sprint cycle in the same manner.
To estimate a timeline for the end of the project, a burn down chart is created. This chart points out to the number of sprints, the time taken to complete each sprint and the time remaining to complete the project, this is very helpful to keep the team in pace with their targeted release date.
These processes are integral to the agile software development methodology. With a faster and wider adoption of the agile methodology across software companies around the world, it is important you understand and know the basic functionalities of these methods. Depending on projects, you can consider adopting the XP methodology, Scrum, or a combination of both. Or you could reach out to software developments services that are deft at utilizing these methodologies.