In the last post I defined two Agile software development best practices I believe provide value to a wide variety of development teams.   Here I define three more practices that I believe are also important when transitioning to Agile Software Development; collocation, unit testing, and refactoring.

Best Practice for Agile Software Development: Collocation

Collocation is simply having everybody on a cross functional team in close proximity to each other. This compounds the coordination benefit of cross functional teams. This is orthogonal to outsourcing. Whether you are outsourcing or not, collocation only refers to whether a particular cross functional team is sitting near each other.

Best Practice for Agile Software Development: Unit Testing

Unit tests are simply tests that exercise small amounts of isolated functionality. That is, if you have a function that adds two numbers, instead of depending on running a user function that eventually calls the function, exercise the function directly. This often requires the use of mock objects that pretend to be things that the function needs in order to test the function in isolation from other functions that it depends on.

The cost of unit tests is in writing the tests themselves and refactoring code as new functionality is introduced to keep the unit tests testing at the right level. The benefit is that you can easily test changes quickly to find simple problems before doing more thorough and slower testing. It also provides a good safety net for refactoring, gets developers more involved in testing, and usually improves the design of the software.

Best Practice for Agile Software Development: Refactoring

Refactoring is the practice of continuously improving the usability, maintainability, and adaptability of code without changing its behavior. That makes it much easier to add new and unanticipated functionality. Refactoring has the disadvantage that it takes extra effort and requires changing the code. Any change has the potential to reduce the maturity and stability of the product, especially if you don’t have adequate testing in place. That’s why refactoring is usually paired up with unit testing and together these are frequently combined with continuous integration.