Customer satisfaction is a subjective requirement that may vary depending on the customer's expectations, preferences, and perceptions. It is not a measurable or testable requirement and therefore it is difficult to verify and validate. Subjective requirements entail a high level of risk of being successfully accomplished, as they may not be clearly understood, agreed upon, or met by the project team and stakeholders. To reduce this risk, the business analyst should work with the customer and other stakeholders to define more specific, objective, and measurable requirements that reflect the customer's needs and expectations for the project deliverable. Reference:
Business Analysis Expert Certification, CCBA| IIBA, section "CCBA Competencies" A Guide to the Business Analysis Body of Knowledge (BABOK Guide), version 3, section 4.2 "Plan Business Analysis Approach" and section 5.1 "Prepare for Elicitation"