The process of requirements management is a critical aspect for the successful completion of a project. If project managers do not accurately determine all of the project requirements, then the chances of the project succeeding are rather remote. It therefore becomes essential for the project managers to correctly ascertain what the requirements are, document the requirements, organize and prioritize them, and closely monitor to effect any changes that may be necessary as the project work advances.
Requirements management as per the widely accepted definition is "the process of identifying, recording, documenting, analyzing, prioritizing and agreeing on requirements and then controlling change and communicating to relevant stakeholders." (Source: Wikipedia)