ANSWER

The BABOK categorizes (requirements types) as follows:

1. Business Requirements
2. Stakeholder Requirements
3. Solution Requirements
   1. Functional Requirements
   2. Non-Functional Requirements
4. Transition Requirements

Business Requirements are high-level statements that describe the goals and objectives of the business and the enterprise level.  A few key points are:

• Business Requirements define WHAT the business is trying to achieve
• In turn, Business Requirements define WHY a project should be undertaken or a solution implemented
• Business Requirements define the metrics that will be used to measure success
• Business Requirements are at the enterprise level and do not define requirements that are specific to any particular group of stakeholders within the organization

Stakeholder Requirements define the needs of a particular group of stakeholders and what they require of a particular solution.  They are not always so different from Solution requirements except that they are from a stakeholders perspective and they show clear traceability to the business requirements.  This is important since business requirements can be achieved in many different ways.  This sometimes requires a compromise between competing needs of different stakeholder groups for the greater good of the enterprise. In this way Stakeholder Requirements are the bridge between business requirements and solution requirements. A few key points are:

• Stakeholder Requirements define WHAT each specific stakeholder/group needs from a solution
• Stakeholder Requirements identify the use cases of a solution
• Stakeholder Requirements are the bridge between business requirements and solution requirements

Solution Requirements describe what characteristics a solution will have to meet the needs of the stakeholders and business.  Similar to how multiple scenarios of stakeholder requirements could satisfy a business requirement, hence the need to translate and trace stakeholder requirements to business requirements, also multiple scenarios of solution requirements could satisfy a stakeholder requirement, hence the need to translate and trace stakeholder requirements to solution requirements. A few key points:

• Solution Requirements describe WHAT characteristics the solution will support.
• From a stakeholder perspective the Solution Requirements may be viewed as describing HOW the Solution Requirements will meet the stakeholder need, but even from this perspective it would define the HOW logically and at a high level rather than give details of the implementation of the solution

Solution Requirements can be further categorized into:

• Functional Requirements which describe the behavior of the solution and the information managed.   In the case of a system, these are the features and functions of the system.
• Non-Functional Requirements define the qualities of the solution or the environmental conditions under which the solution will remain effective. In terms of a technical system solution this often refers to characteristics of capacity, speed, security, availability, etc.

Transition Requirements define characteristics that a solution must have in order to transition from the current state to the desired future state.  These are characteristics that will not be needed once the transition is completed.  A few key points:

• Transition requirements are temporary
• Transition requirements place an emphasis on change management processes