CSC/ECE 517 Fall 2012/ch2a 2w5 dp

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Contents

Agile Software Development

Introduction

Why Agile?

James Shore and Shane Warden [1] state that the benefit for developers to follow a Agile software development process is to deliver successful products to the client or customer. He defines success into 3 types:

  1. Organizational
    • Deliver value and decrease costs to increase return on investment.
  2. Technical
    • Elegant and maintainable code is produced.
  3. Personal
    • Developers find the project fun and rewarding which lead them to be intrinsically motivated and devote passion to the work.

The Agile Manifesto

The Agile Manifesto is a set of 12 principles that provide a foundation for agile methodologies.

The core principles of the manifesto are as follows [2] :

Values

There are four concepts that represent the main values of Agile software development.

  1. Adaptability
  2. Transparency
  3. Simplicity
  4. Unity

Agile poster.png

Adaptability

Adaptability is purported to be the most important value [3] of Agile methodologies.

This value forces teams to plan for inevitable change in a mindful manner.

The focus for Adaptability can be summarized by these two principles stated in the Agile manifesto.

There are three components in Adaptability [4] These three components must ALL be open to change in order to have a fully adaptable agile environment.

  1. Product - quality code and adequate testing will ensure product functionality after changes have been made.
  2. Process - practices that allow the team to adapt must be in place.
  3. People - developers, management, and stakeholders must have the proper attitude that is accepting of change and want to work in a collaborative way. If people don't collaborate, the full advantages of an adaptive process are lost.

Transparency

Transparency in an Agile environment extends from simple communication between individuals working on the project to the project's definition and mission statement itself.[5]

The high value on Transparency can be summarized by these two principles stated in the Agile manifesto.

Transparency in Agile project management is intended to create an open environment where communication and accountability are highly prized. Agile does not limit embracing this value simply to interaction between developers and project managers. As the second bullet point alludes to, this value extends to customer interaction as well. The idea is to generate a unifying project goal that the developers, project managers and, customer can all identify with.

Simplicity

The Agile Manifesto refers to simplicity as, the art of maximizing the amount of work not done is essential. [2]

Simplicity is generally referred to as a little bit less than just enough process. The Agile methodologies attempt to keep the project focused on progressing to the project while eliminating process that can unintentionally slow development. This all plays into the Agile Manifesto's statement of "Working software over comprehensive documentation"

There are three aspects or faces to simplicity [6]

Unity

Unity is a pervading ideal through most everything the Agile method is intended to accomplish. The value placed on unity is reflected in how Agile strives to create a team of customers, developers and project managers that have a single goal of completing a specific project. In addition it is focused on bringing the product team's understanding, goals and, communication in line with the customer's expectations and goals for the project itself. By working together while sharing experiences, knowledge and ideas Agile strives to provide a product that accomplishes the goal that the project was intended to accomplish.

Best Practices

These are some of today's most common Agile practices [7]. Before adopting a practice, teams must be able understand their priorities and problems affecting the product before you can decide which practices will be the solutions to those problems [8].

Popular Agile Methods

Martin Fowler refers to Agile Software Development as a philosophy from which several different types of methodologies inherit their characteristics. Thus, it should be considered as an umbrella for the agile methods organizations choose to implement in their software projects [9].

The following are some of the most common Agile Methods practiced by industry organizations.

Extreme Programming (XP)

Extreme Programming (XP) is one of the most practiced and well-known Agile methods and it is characterized by four core values [10]:

XP's emphasis is on technical practices to ensure frequent delivery of functional software through skillful development. The practice of constant code reviews plays a big part in XP to ensure that development is skillful and code is fully functioning. This requires a high level of teamwork from team members and, therefore, a large fous on pair programming and refactoring must be in place. All three components allow teams to develop designs that increase business value in a simple and effective manner. XP is characterized by short iterations that last anywhere between one and four weeks.

Scrum

Scrum is an agile method for product development that focuses on individuals and teams.

Project development generally occurs in small iterative pieces. The intention is to encourage creativity while providing built in design time for feedback analysis. Scrum provides a simple framework to guide developers and managers during product development. The goal of the simple framework is to provide just enough structure for empirical process control based off of feedback loops.[11]

The fundamental process is defined by the three following roles[12]

Crystal

Crystal is a a variety of sets of methods developed by Alistair Cockburn in the '90s. Each variation's primary focus on improving performance is done through communication between people and their talents over the process in which a team follows [13].

The Crystal methods prioritize safety in a project's outcome, efficiency, and habitability. These priorities motivate a focus on frequent delivery, reflective improvement, and close communication [9].

The name Crystal represents the different facets (like that of a gemstone) or methods available that focus around a central core. The belief that different approaches are required as the criticality [9] and the following of a project vary [13]:

Criticality can be classified as defects causing the loss or affecting the state of [13]:

  1. Comfort
  2. Discretionary money
  3. Essential money
  4. Life

Each version is assigned a color and it represents intensity of the degree of communication required among size of the team to get the job done. The different colors include Crystal Clear, Yellow, Orange and Red [13]. The Crystal methods present an outline of what teams should focus on instead of a comprehensive guide [9].

As teams grow, the method hardens and more restraints must be put in place. Some agility may be lost, but because of a team's common mindset and understanding, the method remains Agile [13].

Lean Development

Lean Development is a top-down approach based on lean processes (also referred to as the Toyota Production System [9]) used in the automotive industry of the 1980s. It was started by Bob Charette and its focus is to provide a set management ideas and reasonings while the development process (team size, iteration length, team distribution, and criticality) is left untouched. The management guidelines Lean Development provides are [13]:

  1. Customer Satisfaction is the top priority
  2. Provide the biggest value for the money
  3. Active customer participation will lead to success
  4. Projects are a team effort
  5. Everything is changeable
  6. Domain, not point, solutions
  7. Don't just construct, complete a project
  8. 80% solution today is better than a 100% solution tomorrow
  9. Be minimalist
  10. Needs determine technology
  11. Product growth is feature growth, not size growth.
  12. Never try to go beyond the limits of Lean Development

References

  1. Shore, James and Warden, Shane. The Art of Agile Development. O’Reilly Media, Inc., 2008, p. 4.
  2. 2.0 2.1 Manifesto for Agile Software Development http://agilemanifesto.org/
  3. The Agile Leader: Adaptability http://blogs.forrester.com/tom_grant/11-04-19-adaptability_may_turn_out_to_be_agiles_most_important_virtue
  4. Adaptation in project management through agile http://searchsoftwarequality.techtarget.com/feature/Adaptation-in-project-management-through-agile
  5. The Concept of Transparency in Agile Project Management http://p-a-m.org/2012/03/the-concept-of-transparency-in-agile-project-management/
  6. Agile Software Development and the Three Faces of Simplicity http://www.informit.com/articles/article.aspx?p=25944
  7. Professional Management: Top ten agile best practices http://profmgmt.wordpress.com/2007/01/11/top-ten-agile-best-practices/
  8. Professional Management: Which best practice to implement first? http://profmgmt.wordpress.com/2007/01/11/which-best-practice-to-implement-first/
  9. 9.0 9.1 9.2 9.3 9.4 Flavors of Agile Development http://martinfowler.com/articles/newMethodology.html#FlavorsOfAgileDevelopment
  10. A Practical Guide to Seven Agile Methodologies, Part 1 http://www.devx.com/architect/Article/32761/0
  11. Scrum - Wikipedia http://en.wikipedia.org/wiki/Scrum_(development)
  12. Scrum.org http://www.scrum.org/Resources/What-is-Scrum
  13. 13.0 13.1 13.2 13.3 13.4 13.5 An Introduction to Agile Methods http://www.cs.umd.edu/~mvz/cmsc435-s09/pdf/agile-paper.pdf
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