Agile development risks

There is no doubt that short iterations are great for preventing feature creep and for pushing the team to meet their commitments, but at what cost? In my experience, the biggest risk of agile development is the tendency to become too focused on the short term goals of the project, ignoring the longer term vision and key non-functional requirements.

When an iteration deadline is approaching, the team is focused on the immediate tasks (and rightfully so!). Unfortunately this means that non-functional requirements such as "the system should be scalable" or "the system should be maintainable" tend to take a backseat to the more concrete "implement feature XYZ" style of functional requirements. If the non-functional requirements are ignored for too many iterations, the cost of recovering can become incredibly high. Agilistas tend to overplay the "we can refactor this later" line when trying to dodge non-functional requirements. Refactoring is a key tool in the developers toolkit, but it should never be used as an excuse for ignoring non-functional requirements.

In order to mitigate this risk, it's important to regularly review the bigger picture with the entire team. Determine if the team is spending enough of their energy on the project's non-functional requirements, and identify and refine the non-functional requirements as a group.

Other semi-related software development resources

http://www.joelonsoftware.com/articles/AardvarkSpec.html

http://agilemanifesto.org/

http://www.infoq.com/news/2008/11/nonfunctional-requirements