What is Agile Scrum?

• What is Scrum?

Scrum is an agile approach to software development. Rather than a full process or methodology, it is a framework. So instead of providing complete, detailed descriptions of how everything is to be done on the project, much is left up to the software development team. This is done because the team will know best how to solve the problem they are presented. This is why, for example, a sprint planning meeting is described in terms of the desired outcome (a commitment to set of features to be developed in the next sprint) instead of a set of Entry criteria, Task definitions, Validation criteria, and Exit criteria (ETVX) as would be provided in most methodologies.

Scrum relies on a self-organizing, cross-functional team. The scrum team is self-organizing in that there is no overall team leader who decides which person will do which task or how a problem will be solved. Those are issues that are decided by the team as a whole. The team is cross-functional so that everyone necessary to take a feature from idea to implementation is involved.
These agile development teams are supported by two specific individuals: a ScrumMaster and a product owner. The ScrumMaster can be thought of as a coach for the team, helping team members use the Scrum framework to perform at their highest level. The product owner represents the business, customers or users and guides the team toward building the right product.
Scrum projects make progress in a series of sprints, which are timeboxed iterations no more than a month long. At the start of a sprint, team members commit to delivering some number of features that were listed on the project's product backlog. At the end of the sprint, these features are done--they are coded, tested, and integrated into the evolving product or system. At the end of the sprint a sprint review is conducted during which the team demonstrates the new functionality to the product owner and other interested stakeholders who provide feedback that could influence the next sprint.

• What are the main activities in Scrum?

The sprint itself is the main activity of a Scrum project. Scrum is an iterative and incremental process and so the project is split into a series of consecutive sprints. Each is timeboxed, usually to between one week and a calendar month. A recent survey found that the most common sprint length is two weeks. During this time the team does everything to take a small set of features from idea to coded and tested functionality.
The first activity of each sprint is a sprint planning meeting. During this meeting the product owner and team talk about the highest-priority items on the product backlog. Team members figure out how many items they can commit to and then create a sprint backlog, which is a list of the tasks to perform during the sprint.
On each day of the sprint, a daily scrum meeting is attended by all team members, including the ScrumMaster and the product owner. This meeting is timeboxed to no more than fifteen minutes. During that time, team members share what they worked on the prior day, will work on today, and identify any impediments to progress. Daily scrums serve to synchronize the work of team members as they discuss the work of the sprint.
At the end of a sprint, the teams conducts a sprint review. During the sprint review, the team demonstrates the functionality added during the sprint. The goal of this meeting is to get feedback from the product owner or any users or other stakeholders who have been invited to the review. This feedback may result in changes to the freshly delivered functionality. But it may just as likely result in revising or adding items to the product backlog.
Another activity performed at the end of each sprint is the sprint retrospective. The whole team participates in this meeting, including the ScrumMaster and product owner. The meeting is an opportunity to reflect on the sprint that is ending and identify opportunities to improve in the new sprint.

• What are the main artifacts of a Scrum project?

The primary artifact of a Scrum project is, of course, the product itself. The team is expected to bring the product or system to a potentially shippable state at the end of each sprint.
The product backlog is a complete list of the functionality that remains to be added to the product. The product backlog is prioritized by the product owner so that the team always works on the most valuable features first. The most popular and successful way to create a product backlog is to populate it with user stories, which are short descriptions of functionality described from the perspective of a user or customer.
On the first day of a sprint and during the sprint planning meeting, team members create the sprint backlog. The sprint backlog can be thought of as the team's to-do list for the sprint. Whereas a product backlog is a list of features to be built (often written in the form of user stories), the sprint backlog is the list of tasks the team needs to perform in order to deliver the functionality they committed to deliver during the sprint.
Two other primary artifacts are the sprint burndown chart and release burndown chart. Burndown charts show the amount of work remaining either in a sprint or a release. They are a very effective tool for determining at a glance whether a sprint or release is on schedule to have all planned work finished by the desired date.

• What are the main roles on a Scrum team?

Even if you are new to Scrum, you may have heard of a role called ScrumMaster. The ScrumMaster is the team's coach and helps team members achieve their highest level of performance. A ScrumMaster differs from a traditional project manager in many key ways, including that the ScrumMaster does not provide day-to-day direction to the team and does not assign tasks to individuals. A good ScrumMaster shelters the team from outside distractions, allowing team members to focus maniacally during the sprint on the goal they have selected.
While the ScrumMaster focuses on helping the team be the best that it can be, the product owner works to direct the team at the right goal. The product owner does this by creating a compelling vision of the product and then conveying that vision to the team through the product backlog.
The product owner is responsible for ensuring that the product backlog remains prioritized as more is learned about the system being built, its users, the team, and so on.
The third and final role on a Scrum project is the team itself. Although individuals on a Scrum team may come to that team with various job titles, while on the team those titles are insignificant. Each person contributes in whatever ways they best can to complete the work of each sprint. This does not mean that a tester will be expected to rearchitect the system; individuals will spend most (and sometimes all) of their time working in whatever discipline they worked before adopting Scrum. But on a Scrum team, individuals are expected to work beyond their preferred disciplines whenever doing so would be for the good of the team.
One convenient way to think of the interlocking nature of these three roles is as a race car. The team is the car itself, ready to speed along in whatever direction it is pointed. The product owner is the driver, making sure that the car is always going in the right direction. The ScrumMaster is the chief mechanic, keeping the car well-tuned and performing at its best.