Agile Software Engineering

Agile Software Engineering

• Agile software engineering focuses on delivering functionality quickly, responding to changing product specifications, and minimizing development overheads.
• There is no 'best' agile method or technique; it depends on who is using the technique, the development team, and the type of product being developed.

Agile Methods

• Agile methods were developed in the 1990s to address the limitations of plan-driven development, which involves significant overheads and documentation.
• Agile methods focus on the software rather than its documentation, develop software in a series of increments, and aim to reduce process bureaucracy as much as possible.

Agile Manifesto

• The Agile Manifesto values:
  • Individuals and interactions over processes and tools
  • Working software over comprehensive documentation
  • Customer collaboration over contract negotiation
  • Responding to change over following a plan

Incremental Development

• All agile methods are based on incremental development and delivery.
• Product development focuses on software features, with a feature doing something for the software user.
• Incremental development involves prioritizing features, implementing the most important features first, and delivering the system increment.

Incremental Development Activities

• Choose features to be included in an increment
• Refine feature descriptions
• Implement and test
• Integrate feature and test
• Deliver system increment

Agile Development Principles

• Involve the customer closely with the software development team.
• Embrace change and adapt the software to cope with changes as they are made.
• Develop and deliver incrementally, testing and evaluating each increment as it is developed.
• Maintain simplicity in both the software being developed and in the development process.
• Focus on people, not things, and trust the development team.

Extreme Programming (XP)

• XP is an influential agile method that focuses on rapid, incremental software development, change, and delivery.
• XP techniques include:
  • Test-first development
  • Continuous integration
  • Refactoring
  • Incremental planning/user stories
  • Small releases
  • Collective ownership
  • Pair programming
  • On-site customer
  • Sustainable pace

Scrum

• Scrum is an agile method that provides a framework for agile project organization and planning.
• Scrum does not mandate any specific technical practices.
• Scrum terminology includes:
  • Product
  • Product owner
  • Product backlog
  • Development team
  • Sprint
  • Scrum
  • ScrumMaster
  • Potentially shippable product increment
  • Velocity

Scrum and Sprints

• In Scrum, software is developed in sprints, which are fixed-length periods (2-4 weeks) in which software features are developed and delivered.
• Sprints should produce a 'shippable product increment'.

Product Backlogs

• The product backlog is a list of what needs to be done to complete the development of the product.
• The product backlog may include a variety of different items, such as product features, user requests, essential development activities, and desirable engineering improvements.
• The product backlog should always be prioritized.

Product Backlog Items

• Examples of product backlog items include:
  • Features to be implemented
  • User requests
  • Development activities
  • Engineering improvements

Product Backlog Item States

• Ready for consideration: high-level ideas and feature descriptions that will be considered for inclusion in the product.
• Ready for refinement: the team has agreed that this is an important item that should be implemented, but requires further refinement.
• Ready for implementation: the PBI has enough detail for the team to estimate the effort involved and to implement the item.### Agile Software Engineering
• Agile software engineering methods are geared towards rapid product development and delivery.
• Agile methods are based on iterative development and minimizing overheads during the development process.

Extreme Programming (XP)

• XP is an influential agile method that introduced agile development practices.
• Practices include:
  • User stories
  • Test-first development
  • Continuous integration

Scrum

• Scrum is an agile method that focuses on agile planning and management.
• Unlike XP, Scrum does not define the engineering practices to be used.
• The development team may use any technical practices they believe are appropriate for the product being developed.

Product Backlog

• The product backlog is a list of work items to be completed.
• Each increment of the software implements some of the work items from the product backlog.

Sprint

• Sprints are fixed-time activities (usually 2-4 weeks) where a product increment is developed.
• Increments should be 'potentially shippable' i.e., they should not need further work before they are delivered.

Self-Organizing Team

• A self-organizing team is a development team that organizes the work to be done by discussion and agreement amongst team members.

Sprint Activities

• Sprint planning:
  • Establish an agreed sprint goal
  • Decide on the list of items from the product backlog to be implemented
  • Create a sprint backlog
• Sprint execution:
  • Work on the sprint backlog items
  • Implement the product backlog items
• Sprint reviewing:
  • Review the work done during the sprint
  • Identify new problems and issues
  • Reflect on how to improve the way they work

Scrum Meeting

• Daily Scrum (also known as Daily Stand-up):
  • A short, daily meeting to coordinate the team's work
  • Share information, describe progress, and plan for the day
  • Review the sprint backlog

Sprint Goals

• Sprint goals may be focused on:
  • Software functionality
  • Support
  • Performance and reliability

Agile Activities

• Test automation:
  • Automate product testing as much as possible
  • Develop a suite of executable tests
• Continuous integration:
  • Integrate software components immediately
  • Test the system to check for unanticipated component interaction problems

Code Completeness Checklist

• Reviewed:
  • Code has been reviewed by another team member
  • Checked for coding standards, understandability, and comments
• Unit tested:
  • All unit tests have been run automatically
  • All tests have executed successfully
• Integrated:
  • Code has been integrated with the project codebase
  • No integration errors reported
• Integration tested:
  • All integration tests have been run automatically
  • All tests have executed successfully
• Accepted:
  • Acceptance tests have been run (if appropriate)
  • Product owner or development team has confirmed the product backlog item has been completed

Team Size and Composition

• Ideal Scrum team size is between 5 and 8 people
• Teams should have diverse skills and experience
• Team members should be able to communicate informally and effectively

External Interactions

• Scrum assumes that the ScrumMaster and Product Owner should be involved in external interactions
• The team should focus on development and minimize external interference or distractions

Project Management

• In larger companies, there is a need for development teams to report on progress to company management
• The ScrumMaster may have to take on project management responsibilities
• Project management responsibilities include:
  • Reporting
  • Budgeting
  • Scheduling
  • Risk management
  • Progress tracking