Tips for Writing Functional Requirements

The first tip for writing functional requirements is - keep it simple. Most people don't like to read, so by not adding too much detail, you increase the odds that your functional requirements will be read. As much as possible, keep technical jargon to a minimum. Also, Keep in mind that your project stakeholders - system users and owners- will have to verify the requirements to ensure they meet the needs of the business. Keeping details to a minimum helps speed this process along.

Although' "a picture is worth a thousand words" is an overused cliche it does hold true for writing functional requirements. Utilizing pictures is often called structuring the functional requirements. Illustrating (drawing) the functional requirements of a system helps to accurately depict them in a universal way, that all parties involved in the development of the system are able to understand.

An alternative to structuring functional requirements (and oftentimes a prerequisite) to system modeling is prototyping. When users have difficulty expressing the necessary facts needed to draw an adequate illustration of the functional requirement, a prototype can serve as an alternative or complementary approach. Prototyping is used to build sample inputs and outputs. The logic behind prototyping is that users will recognize their requirements when they see them.

Getting feedback by circulating functional requirements helps to gather stakeholder buy in. Attaching a deadline can help to assure that the necessary feedback is obtained in a timely manner, thus ensuring the project stays on schedule. Setting up a project design meeting to go over functional requirements is an alternative to circulating them. Invite everyone who should be there. Make sure you emphasize the importance of attending the meeting to ensure their requirements are taken into account.

The fourth tip for writing functional requirements is to use bullet points. This tip goes back to tip number one - keep it simple. Bullet points are direct, simple, and easy for people to read. Bullet points help the reader focus on the most important aspect of the requirement. This does not mean you should not include details if necessary. It will behoove you to add details and any specifics on a supplementary report.

The last tip for writing functional requirement is to organize them into groups. Depending on the system or process that is being developed, your requirements grouping will vary. Possible grouping for functional requirements are:

• Group by functional areas of the system
• Grouping requirements by outputs
• Grouping requirements by inputs

There is no perfect way to group requirements. The best way is a system that you're comfortable with, and one that effectively communicates the functional requirements of the users.