Completeness is one of the characteristics of good requirements, along with clarity, consistency, correctness, feasibility, testability, traceability, and prioritization. Completeness means that the requirements specify everything that is necessary and relevant for the solution, and that there are no gaps, omissions, or ambiguities in the requirements. A BA can ensure completeness by using various techniques, such as:
Reviewing the requirements with stakeholders and subject matter experts to verify that they cover all the business needs and objectives, and that they are aligned with the solution scope and vision
Validating the requirements against the business case, the project charter, and other relevant documents to confirm that they are consistent and coherent with the project goals and deliverables
Analyzing the requirements for dependencies, assumptions, constraints, risks, and issues, and documenting them appropriately
Using models, diagrams, and prototypes to illustrate the requirements and identify any missing or unclear aspects
Applying quality standards and criteria to evaluate the requirements and ensure that they meet the expectations and requirements of the stakeholders
By ensuring completeness, a BA can avoid missing, inconsistent, and contradictory requirements that could lead to confusion, errors, rework, delays, and dissatisfaction among the stakeholders.
References:
[BABOK Guide v3], Section 4.5: Specify and Model Requirements, p. 120-121
CBAP / CCBA Certified Business Analysis Study Guide, 2nd Edition, Chapter 4: Requirements Analysis, p. 153-154
Certified Business Analysis Professional™ (CBAP®) Specialization, Course 2: Business Analysis: Requirements Analysis and Design Definition, Week 1: Requirements Analysis and Design Definition, Video: Characteristics of Good Requirements