Agile Methodology

What is Agile?

Agile software development refers to a group of software development methodologies based on iterative development, where requirements and solutions evolve through collaboration between self-organizing cross-functional teams.
The term was coined in the year 2001 when the Agile Manifesto was formulated.
Agile methods generally promote a disciplined project management process that encourages frequent inspection and adaptation, a leadership philosophy that encourages teamwork, self-organization and accountability, a set of engineering best practices intended to allow for rapid delivery of high-quality software, and a business approach that aligns development with customer needs and company goals.
Conceptual foundations of this framework are found in modern approaches to operations management and analysis, such as lean manufacturing, soft systems methodology, speech act theory (network of conversations approach), and Six Sigma.[

Agile Principles
To help people to gain a better understanding of what agile software development is all about, we can refine the philosophies captured in their manifesto into a collection of twelve principles. These principles are:
1. Our highest priority is to satisfy the customer through early and continuous delivery of valuable software. For some reason many people within IT have seem to have forgotten that the goal of software development should be the development of software. Or, perhaps the problem is that they think that they need to define everything up front before they can start building software, whereas an evolutionary approach to development seems to work much better.
2. Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage. Like it or not, requirements will change throughout a software development project. Traditional software developers will often adopt change management processes which are designed to prevent/reduce scope creep, but when you think about it these are really change prevention processes, not change management processes. Agilists embrace change and instead follow an agile change management approach which treats requirements as a prioritized stack which is allowed to vary over time.
3. Deliver working software frequently, from a week to a couple of months, with a preference to the shorter time scale. Frequent delivery of working software provides stakeholders with concrete feedback, making the current status of your project transparent while at the same time providing an opportunity for stakeholders to provide improved direction for the development team.
4. Business people and developers must work together daily throughout the project. Your project is in serious trouble if you don't have regular access to your project stakeholders. Agile developers adopt practices such as on-site customer and active stakeholder participation, and adopt inclusive tools and techniques which enable stakeholders to be actively involved with software development.
5. Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done. Too many organizations have a vision that they can hire hordes of relatively unskilled people, provide them with a CMMI/ISO/...-compliant process description, and that they will successfully develop software. This doesn't seem to work all that well in practice. Agile teams, on the other hand, realize that you need build teams from people who are willing to work together collaboratively and learn from each other. They have the humility to respect one another and realize that people are a primary success factor in software development.
6. The most efficient and effective method of conveying information to and within a development team is face-to-face conversation. For software development team to succeed its members must communicate and collaborate effectively. There are many ways which people can communicate together, and as you can see face-to-face communication at a shared drawing environment (such as paper or a whiteboard) is the most effective way to do so.
7. Working software is the primary measure of progress. The primary measure of software development should be the delivery of working software which meets the changing needs of its stakeholders, not some form of "earned value" measure based on the delivery of documentation of the holding of meetings.
8. Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely. Just like you can't sprint for an entire marathon, you can't successfully develop software by forcing people to work overtime for months at a time. My experience is that you can only do high-quality, intellectual work for 5-6 hours a day before burning yourself out. Yes, the rest of the day can be filled up with email, meetings, water cooler discussions, and so on, but people's ability to do "real work" is limited. Yes, you might be able to do high-quality work for 12 hours a day, and do so for a few days straight, but after awhile you become exhausted and all you accomplish is 12 hours of mediocre work a day.
9. Continuous attention to technical excellence and good design enhances agility. It's much easier to understand, maintain, and evolve high-quality source code than it is to work with low-quality code. Therefore, Agilists know that they need to start with good code, to keep it good via refactoring, and take a test-driven approach so that they know at all times that their software works. We also adopt and follow development guidelines, in particular coding guidelines and sometimes even modeling guidelines.
10. Simplicity – the art of maximizing the amount of work not done – is essential. Agile developers focus on high value activities, we strive to maximize our stakeholder's return on investment in IT, and we either cut out or automate the drudge work.
11. The best architectures, requirements, and designs emerge from self-organizing teams. This is one of the most radical principles of the agile movement. The Agile Model Driven Development (AMDD) and test-driven design (TDD) methods are the primary approaches within the agile community for ensure the emergence of effective architectures, requirements, and designs.
12. At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behavior accordingly. Software process improvement (SPI) is a continual effort, and techniques such as retrospectives should be adopted to enable you to improve your approach to software development.
Stop for a moment and think about these principles. Is this the way that your software projects actually work? Is this the way that you think projects should work?
Re-read the principles once again. Are they radical and impossible goals as some people would claim, are they meaningless motherhood and apple pie statements, or are they simply common sense? My belief is that these principles form a foundation of common sense upon which you can base successful software development efforts