6.a) Write a short note on Scrum and Crystal.
Answer:
Scrum
- Scrum is an agile software development method that was conceived by Jeff Sutherland and his development team in the early 1990s.
- In recent years, further development on the Scrum methods has been performed by Schwaber and Beedle.
- Scrum principles are consistent with the agile manifesto and are used to guide development activities within a process that incorporates the following framework activities: requirements, analysis, design, evolution, and delivery.
- Within each framework activity, work tasks occur within a process pattern called a sprint.
- The work conducted within a sprint (the number of sprints required for each framework activity will vary depending on product complexity and size) is adapted to the problem at hand and is defined and often modified in real time by the Scrum team.
- The overall flow of the Scrum process is illustrated in Figure 3.4.
- Scrum emphasizes the use of a set of software process patterns that have proven effective for projects with tight timelines, changing requirements, and business criticality. Each of these process patterns defines a set of development actions:
- Backlog—a prioritized list of project requirements or features that provide business value for the customer. Items can be added to the backlog at any time (this is how changes are introduced).
- The product manager assesses the backlog and updates priorities as required.
- Sprints—consist of work units that are required to achieve a requirement defined in the backlog that must be fit into a predefined time-box (typically 30 days)
• Changes (e.g., backlog work items) are not introduced during the sprint. Hence, the sprint allows team members to work in a short-term, but stable environment.
• Scrum meetings—are short (typically 15 minutes) meetings held daily by the Scrum team. Three key questions are asked and answered by all team members :
> What did you do since the last team meeting?
> What obstacles are you encountering?
> What do you plan to accomplish by the next team meeting?
• A team leader, called a Scrum master, leads the meeting and assesses the responses from each person. • The Scrum meeting helps the team to uncover potential problems as early as possible. Also, these daily meetings lead to “knowledge socialization” and thereby promote a self-organizing team structure. • Demos—deliver the software increment to the customer so that functionality that has been implemented can be demonstrated and evaluated by the customer.
• It is important to note that the demo may not contain all planned functionality, but rather those functions that can be delivered within the time-box that was established.
• The Scrum process patterns enable a software team to work successfully in a world where the elimination of uncertainty is impossible.
Crystal:
Alistair Cockburn [Coc05] and Jim Highsmith [Hig02b] created the Crystal family of agile methods15 in order to achieve a software development approach that puts a premium on “maneuverability” during what Cockburn characterizes as “a resource-limited, cooperative game of invention and communication, with a primary goal of delivering useful, working software and a secondary goal of setting up for the next game” [Coc02].
To achieve maneuverability, Cockburn and Highsmith have defined a set of methodologies, each with core elements that are common to all, and roles, process patterns, work products, and practice that are unique to each. The Crystal family is actually a set of example agile processes that have been proven effective for different types of projects. The intent is to allow agile teams to select the member of the crystal family that is most appropriate for their project and environment