Agile and Scrum Overview

Agile Overview

• Agile is a flexible software development method focused on iterative progress, collaboration, and adapting to change.
• Core Agile values prioritize individuals and interactions over processes; working software over comprehensive documentation; customer collaboration over contract negotiation; and responding to change over following a plan.
• Twelve principles of Agile emphasize delivering valuable software quickly and continuously. Changes are welcomed and embraced, working software is delivered frequently (e.g., weekly), process progress is measured by working software, and teams maintain a consistent pace. Communication is prioritized through face-to-face interaction. Motivated individuals and technical excellence are important. Teams that are self-organizing are effective. Reflection and adjustment are important to adapt to change.

Scrum Overview

• Scrum is a development method that organizes work into short periods called sprints, aiming for incremental improvements.
• It was developed by Hirotaka Takeuchi and Ikujiro Nonaka in 1986, drawing inspiration from good manufacturing practices.
• Scrum emphasizes aspects of sequential to iterative development processes where all aspects of development are handled by teams.

Scrum Framework

• Key roles include the Product Owner (liaising with stakeholders and managing the backlog), Scrum Master (facilitating practices, managing meetings, removing obstacles). Developers self-organize to complete sprint goals.
• Artifacts include a Product Backlog (dynamic list of features prioritized by the Product Owner), and Sprint Backlog (tasks planned for the current sprint, signed up for by developers).
• Meetings include a Daily Scrum, Sprint Review and Sprint Retrospective.

Sprint Process

• Sprint Planning involves customer prioritization of work items from the backlog, and developers determining tasks for the sprint backlog.
• Sprint execution occurs over approximately 1-4 weeks.
• A deliverable product version is produced in each sprint.
• Sprint Burn Down tracks sprint progress and Release Burn Down tracks project progress across multiple sprints.

Planning Poker

• Planning Poker is a collaborative estimation technique integral to Agile, used for estimating, reducing anchoring bias, utilizing group intelligence, and enabling consensus-based estimation.

Extreme Programming (XP)

• XP emphasizes high-quality software development within short development cycles and teamwork.
• Key XP practices include test-driven development (writing tests before code, checking functionality), pair programming (two developers collaborating on the same code), continuous integration, small releases, simple designs, and customer collaboration.

Software Cost Estimation and Project Management

• Estimation Quality Factor (EQF) shows accuracy of estimates, while Bias reflects overestimation or underestimation.
• Success rates for projects on time and within budget are relatively low (16%). Success requires user engagement, executive support, and clear requirements.

Failure Factors

• Common project failure factors include poor planning, incomplete requirements, and lack of experienced team members.

Constraint Triangle

• Balancing project time, cost, and quality is central. Improving one usually results in reduction in another.

Mythical Man-Month

• Adding more people to a late project often results in further delays.

Triage

• Prioritization of tasks according to severity and impact, categorized into Must Do, Good to Do, and Nice to Do.

Object-Oriented Design (OO)

• SOLID Principles form the foundation of Object-Oriented Design (OO), covering Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion principles.
• Design Patterns such as Factory, Builder, MVC enhance flexibility and maintainability.

Design Patterns

• MVC is used for separating program into Model (data), View (user interface), and Controller (logic) components. It helps make components easier to fix, update, and reuse. Other design patterns such as Double-Checked Locking are used for concurrency control.
• Abstraction and reuse are central to effective software design.

DRY Principle

• DRY (Don't Repeat Yourself) ensures that data and logic are stored in one clear authoritative place.