Requirements and designs are harmonious tools for crafting effective solutions that address organizational needs.

Requirements serve as the foundation, capturing the essence of what stakeholders require to achieve their objectives or address their problems. They guide the decisions to be made by outlining the functionalities, constraints, and expectations of the desired outcome.

Designs, on the other hand, transform these requirements from representative inputs into actionable initiatives, plans, and systems that model the structure, components, and architecture of a proposed solution.

4.4.1 Working with Requirements and Designs

Requirements and designs can be represented as an artifact, a set of documents, or a variety of models. Since they are similar in nature, it is important to understand the differences between requirements and designs. While the same tasks and techniques can be used to create both, the purposes they serve are unique.

Requirements and designs are interdependent and cyclical. As designs are created, they can reveal new insights that enhance the requirements. Similarly, changing requirements might lead to updates in the design. This ongoing feedback loop ensures that both requirements and designs stay aligned and are continually refined throughout the initiative.

Examples:

4.4.2 Requirement Classification

As mentioned above, a requirement is “a usable representation of a need.” The BABOK® Guide lists four main requirement types–business, stakeholder, solution (including functional and nonfunctional requirements), and transition requirements. In addition to these, business analysis can help an enterprise meet its commitment to sustainability.

4.4.2.1 Business Requirements:

Statements of goals, objectives, and outcomes for why a change has been initiated. They can apply to the whole enterprise, a business area, or a specific initiative.

4.4.2.2 Stakeholder Requirements:

The needs of stakeholders that must be met to achieve the business requirements. They may serve as a bridge between business and solution requirements.

4.4.2.3 Solution Requirements:

The capabilities and qualities of a solution that meet the stakeholder requirements. They provide the detail to allow for the development and implementation of the solution. Solution requirements can be:

4.4.2.3.1 Functional Requirements: the capabilities a solution must have for the behaviour and information the solution will manage.

4.4.2.3.2 Non-functional Requirements or Quality of Service Requirements: conditions or qualities a solution must have. See BABOK Guide, 10.30 Non-Functional Requirements Analysis

4.4.2.4 Transition Requirements:

The capabilities and the conditions needed to facilitate a transition from the current to the future state. They are temporary and address areas such as data conversion, training, and business continuity.

4.4.3 Tracing Requirements and Designs

Traceability is the ability for tracking the relationships between requirements and designs from the original stakeholder need to the actual implemented solution. Traceability supports change control by ensuring the source of a requirement or design can be identified and other related requirements and designs potentially affected by a change are known. 

It is difficult to accurately represent needs and solutions without considering their relationships. The traceability of requirements and designs is used to identify and document the lineage of each requirement and design, including its backward traceability to the original business need, its forward traceability to the solution components, and its relationship to other requirements and designs. Traceability can help ensure the solution conforms to requirements and designs and can assist in scope, impact, change, risk, time, cost, and communication management.

Organizations often trace their requirements and designs using a traceability modelling structure. A traceability model enables bi-directional tracking of requirements and designs by visually linking them to the business need and solution components through matrices and diagrams. Using a traceability model helps to detect missing requirements and designs or identify solution components that are not supported by any requirement or design.