The purpose of this discipline is to:

• Understand the problem to be solved
• Understand stakeholder needs (what users want)
• Define the requirements for the solution (what the system must do)
• Define the boundaries (scope) of the system
• Identify external interfaces for the system
• Identify technical constraints on the solution
• Provide the basis for planning iterations
• Provide the initial basis for estimating cost and schedule

To achieve these goals, it is important to understand the definition and scope of the problem that you are trying to solve. Identify Stakeholders and define the problem to be solved. Having agreed on the problem to be solved, the Requirements for the system are elicited, organized, analyzed, validated, and specified.

Throughout the lifecycle, you manage changes to the requirements.The Requirements discipline is related to the other disciplines in the following ways:

• The Architecture and Development disciplines get their primary input from the Requirements discipline.
• The Test discipline validates the system against the requirements.
• The Project Management discipline plans the project and assigns requirements to each iteration by analyzing the prioritized requirements and assigning work.