1. Collaborating closely with both our stakeholders and with other developers. We do this to reduce risk through tightening the feedback cycle and by improving communication via closer collaboration.
2. Implementing functionality in priority order. We allow our stakeholders to change the requirements to meet their exact needs as they see fit. The stakeholders are given complete control over the scope, budget, and schedule – they get what they want and spend as much as they want for as long as they're willing to do so.
3. Analyzing and designing. We analyze individual requirements by model storming on a just-in-time (JIT) basis for a few minutes before spending several hours or days implementing the requirement. Guided by our architecture models, often hand-sketched diagrams, we take a highly-collaborative, test-driven design (TDD) approach to development (see Figure 9) where we iteratively write a test and then write just enough production code to fulfill that test. Sometimes, particularly for complex requirements or for design issues requiring significant forethought, we will model just a bit ahead to ensure that the developers don't need to wait for information.
4. Ensuring quality. Disciplined agilists are firm believers in following guidance such as coding conventions and modeling style guidelines. Furthermore, we refactor our application code and/or our database schema as required to ensure that we have the best design possible.
5. Regularly delivering working solutions. At the end of each development cycle/iteration you should have a partial, working solution to show people. Better yet, you should be able to deploy this solution into a pre-production testing/QA sandbox for system integration testing. The sooner, and more often, you can do such testing the better. See Agile Testing and Quality Strategies: Discipline Over Rhetoric for more thoughts.
6. Testing, testing, and yes, testing. As you can see in Figure 10 agilists do a significant amount of testing throughout construction. As part of construction we do confirmatory testing, a combination of developer testing at the design level and agile acceptance testing at the requirements level. In many ways confirmatory testing is the agile equivalent of "testing against the specification" because it confirms that the software which we've built to date works according to the intent of our stakeholders as we understand it today. This isn't the complete testing picture: Because we are producing working software on a regular basis, at least at the end of each iteration although ideally more often, we're in a position to deliver that working software to an independent test team for investigative testing. Investigative testing is done by test professionals who are good at finding defects which the developers have missed. These defects might pertain to usability or integration problems, sometimes they pertain to requirements which we missed or simply haven't implemented yet, and sometimes they pertain to things we simply didn't think to test for.