- Produce working software on a regular basis. This is one of the 12 principles behind the Agile Manifesto, and in my experience is a critical differentiator between the teams that are agile and those that are merely claiming it. Ideally the team should produce potentially shippable software each iteration. That doesn't mean that they'll deploy the system into production, or the marketplace, each iteration but they could if required to do so. Typically the team will deploy into a pre-production testing environment or a demo enviroment at the end of each iteration (or more often for that matter).
- Do continuous regression testing, and better yet take a Test-Driven Development (TDD) approach. Agile developers test their work to the best of their ability, minimally doing developer regression testing via a continuous integration (CI) strategy and better yet do developer-level TDD. This approach enables development teams to find defects early, thereby reducing the average cost of addressing the defects, it also helps them to deliver higher quality code and to move forward safely when adding or changing functionality.
- Work closely with their stakeholders, ideally on a daily basis. A common practice of agile teams is to have an on-site customer or product owner who prioritizes requirements and provides information on a timely manner to the team. Disciplined agile teams take it one step further and follow the practice active stakeholder participation where the stakeholders get actively involved with modeling and sometimes even development. Note that some project teams will be working with stakeholder representatives, such as a product owner or product manager, instead of directly with stakeholders (still, try to get direct access).
- Are self-organizing within a governance framework. Agile teams are self-organizing, which means that the people doing the work determines how the work will be done, they're not told by a manager who may not even be directly involved with the work how it will be done. In other words the team does its own planning, including scheduling and estimation. Disciplined agile teams are self governing within an effective governance framework.
- Regularly reflect on how they work together and then act to improve on their findings. Most agile teams hold a short meeting at the end of each iteration to reflect upon how well things are working and how they could potentially improve the way that they are working together. Sometimes this is done in a more formalized manner in the form of a retrospective, but often it's done informally. The team then acts on one or more of their suggested improvements the next iteration. Disciplined agile teams take this one step further and measure their software process improvement (SPI) progress over time: the act of taking these measures, perhaps via a product such as Rational Self Check, helps to keep the team on track in their SPI efforts.
I have yet to discover an ad-hoc development team which met all five criteria, and most of them rarely meet two or three.
- Results from the 2010 How Agile Are You? survey which explored these criteria in detail
- How Agile Are We Really? discusses the results from the above survey
- Lean Development Governance
- Examining the Agile Manifesto
- Norm Kerth's Retrospectives Home Page
- Measured Capability Improvement Framework (MCIF)