Requirements Definition (RD) vs. Requirements Management (RM)

requirements definition (RD:) deciding what changes to make to a product and when to make the changes—where change means a set of modifications to the functional design of the product in order to address one or more business problems or meet one or more business needs

requirements management (RM:) keeping track of the changes that are desired to be made, that are being made, and those that have been made to a product

Sustained Focus on the Product: The Key to Making GOOD REQUIREMENTS

Requirements definition (RD,) i.e., making GOOD REQUIREMENTS, is uniquely a whole-team activity — an activity that takes the concerted effort of the whole product team: Business, PMO, IT, and Governance. It can be considered the heart of software development.

RD is an inherently hard activity (perhaps even the hardest activity in software development.)