The best action to take to ensure the design meets customer requirements is to create a system requirements verification matrix to trace the design to the technical requirements and include verification methods. A system requirements verification matrix is a document that maps the design elements to the system requirements, and specifies the methods and criteria for verifying that the design satisfies the requirements.
Verification methods can include inspection, analysis, demonstration, or testing. A system requirements verification matrix can help the business analyst and the project team to ensure the quality and completeness of the design, and to avoid any errors, gaps, or inconsistencies. References: PMI Professional in Business Analysis (PMI-PBA)Examination Content Outline1, page 20; Business Analysis for Practitioners: A Practice Guide2, page 100.