Yes, functional specifications are long and often complex documents, but they are well worth the time. A great analogy often used to express the documents importance is building a house. You have two options: 1.) Hire a construction crew and let them decide how everything will be built, or 2.) hire an architect that will create a blueprint of your needs and personal preferences. It’s that simple. Because we wouldn’t build our home without a customized blueprint, we wouldn’t want to build a website without proper functional documentation.

Functional specifications give clients and development partners an overview of the functionality that is going to be built into a website. This ensures that both parties are on the same page and expectations are accurately set prior to any development work beginning.  The detailed document encompasses all the attributes and functionality from an end-user point of view and explains how people will interact with each part of the website. It also allows for the detection of errors as well as overlooked functionality that was not conceived before the documentation stage.

As a business analyst who writes functional specifications, I frequently bring up questions during the writing phase that should be resolved by the project teams before ever going into development. Typically, the derived questions and functionality gaps touch on a broad range of business, design and technical issues. Without a functional specification, the discovery of these elements would be nonexistent.

In terms of project productivity, efficiency and flexibility the functional specification provides the framework for an accurate timeline. It eliminates concerns and questions about design and development which allows stakeholders to focus on what they do best. Clients know exactly what they’re going to get and developers now have a road map of functionality for development. Additionally, costly last-minute fixes and associated change orders are eliminated or minimized during the implementation phase.

Finally and most importantly, it provides a centralized view of the agreed upon functionality where each person involved in the project can measure results.