The Differences Between Design Verification and Design Review

In the development process of medical devices, design verification and design review play extremely important roles. Although these processes may appear similar at first glance, they differ significantly in their objectives, timing, implementation methods, and deliverables. This article clarifies the distinctions between these two processes and explains their respective importance.

What is Design Verification?

Design verification is a process that objectively evaluates whether a developed medical device meets specified design requirements. This process confirms that the product is “correctly designed.”

Characteristics of Design Verification

Design verification is characterized by several key elements. First, it involves collection of objective evidence through testing, analysis, and inspection to provide objective evidence of requirement fulfillment. Second, it requires quantitative assessment—in most cases, measurable results are obtained against numerical standards. Third, it addresses regulatory requirements, as design verification is a mandatory process in medical device regulations such as the FDA Quality System Regulation (QSR), ISO 13485, and EU MDR/IVDR. Finally, results must be documented to ensure traceability. Particularly for medical devices incorporating software, compliance with IEC 62304 is essential, and an appropriate verification level commensurate with the software safety class (Class A, B, or C) must be ensured.

Timing of Design Verification

Design verification is typically conducted during the later stages of design development. Specifically, it is usually performed after the design is “frozen” and before manufacturing begins. However, for high-risk elements, partial verification may be conducted from the early stages of development. The design verification process works closely with the risk management process based on ISO 14971, with prioritization of verification activities applied to high-risk areas.

What is Design Review?

Design review, by contrast, is a systematic review process that evaluates whether the design at each stage of the design process is appropriate. This process confirms whether “the design direction is correct.”

Characteristics of Design Review

Design review possesses the following characteristics. First, it involves multidisciplinary evaluation, consolidating opinions from different expertise areas and perspectives to evaluate design comprehensively. This process involves participation from multiple functional departments including quality assurance, regulatory affairs, manufacturing, and clinical evaluation. Second, qualitative elements that cannot be easily quantified—such as usability, market fit, and feedback from healthcare professionals—are also evaluated. Third, the process takes a preventive approach by identifying issues early and minimizing the cost of design changes. Finally, specific feedback is provided to the design team for improvement purposes.

Timing of Design Review

Design review is conducted multiple times throughout the entire design process. It is typically performed at major milestones such as completion of conceptual design, completion of detailed design, post-prototype evaluation, and before design freeze. The EU MDR and regulatory authorities expect the design review process to be appropriately documented with full traceability ensured.

Key Differences Between the Two

The following table summarizes the major differences between design verification and design review.

Aspect	Design Verification	Design Review
Objective	To objectively confirm that design outputs meet design inputs (requirements)	To evaluate design progress, identify potential issues, and obtain approval to proceed to the next phase
Implementation Method	Collection of objective data through testing, analysis, calculation, simulation, and inspection	Conducted in meeting format with discussion and evaluation by expert groups
Deliverables	Verification protocols, verification reports, test data, and other technical documents	Review meeting minutes, action item lists, and design approval documents
Timing	Primarily conducted intensively during the later design stages	Conducted multiple times throughout the entire design process
Nature of Evidence	Quantitative and objective data	Qualitative and integrated expert judgment
Key Participants	Test and quality assurance engineers, inspection technicians	Product managers, designers, quality departments, regulatory affairs departments, and manufacturing departments
Documentation Requirements	Detailed test data and report records are essential	Records of discussions, decisions, and approvals are essential

Interrelationship Between the Two

Design verification and design review have a complementary relationship. Design review evaluates the appropriateness of the design verification plan, while the results of design verification serve as important input to design review.

Specifically, in early design reviews, the necessary design verification activities are discussed and a design verification plan is established. At this stage, results from ISO 14971 risk management are referenced, and verification items are prioritized according to risk levels. Subsequently, design verification is conducted, and verification results (test data, test reports, etc.) are submitted to intermediate design reviews. In these intermediate reviews, the validity of the design is evaluated based on the verification results. Finally, the design verification results serve as the basis for judging product release in the final design review, determining whether the product can be brought to market.

Importance in Medical Device Development

Because medical devices are products that directly impact human life, ensuring their safety and efficacy is of paramount importance. Design verification and design review are essential processes for achieving this goal.

Particularly in medical device regulations, these processes must be appropriately implemented and documented. For example, both the FDA’s Quality System Regulation (QSR) and the European Medical Device Regulation (MDR) explicitly require both processes. Under EU MDR, the technical file must include the results of design verification and design validation, and the adequacy of these processes is subject to inspection by regulatory authorities and Notified Bodies (NBs). In the proposed 2025 amendments, software classification rules are expected to be simplified; however, implementation of appropriate design control processes will continue to be required. Under ISO 13485 and 21 CFR Part 820 (FDA QSR), design verification and design validation are positioned as core processes within medical device quality management systems. Particularly for high-risk medical devices and software-as-a-medical-device (SaMD), appropriate design controls are expected to ensure patient safety.

Practical Examples in the Development Process

Let us consider the development of a new blood glucose meter as an example.

Examples of Design Review

In the conceptual design review, fundamental concepts such as measurement principle, user interface, and overall size are evaluated. This review involves discussion from marketing regarding market fit, from healthcare professionals regarding usability, and from quality departments regarding alignment with risk management. Each perspective contributes to a comprehensive assessment.

In the detailed design review, details such as electrical circuitry, software architecture, and enclosure design are evaluated. This review confirms that design-related risks identified based on ISO 14971 are appropriately implemented and that a software development plan compliant with IEC 62304 has been established.

In the prototype review, design modifications are considered based on prototype evaluation results. Results from usability testing and early-stage performance testing are presented, and the need for improvements is discussed.

In the final design review, product release decisions are made, including manufacturing readiness assessment. The completion status of design verification, progress of clinical evaluation, and establishment of manufacturing processes are all confirmed.

Examples of Design Verification

In accuracy verification, testing is conducted to confirm that measurement accuracy under various conditions meets specified requirements. For example, for a blood glucose meter, this includes accuracy within the measurement range (e.g., 20–600 mg/dL), performance under different temperature and humidity conditions, and performance differences among patient populations (e.g., age, gender, skin characteristics).

In durability verification, testing is conducted to verify durability through drop tests and temperature/humidity cycle tests. This confirms that the medical device maintains stability under typical use environments and under misuse scenarios.

In software verification, testing is conducted to confirm that the software functions according to specifications. In compliance with IEC 62304, verification levels appropriate to the software safety class are implemented (Class A requires basic functional verification; Class B requires a comprehensive testing strategy; Class C requires comprehensive verification including regression testing).

In usability verification, evaluations are conducted with actual users to assess usability. For a blood glucose meter, this includes evaluation of practical operability by diabetic patients and assessment of ease of education and instruction by healthcare professionals.

Conclusion

Design verification and design review are indispensable processes in medical device development. Although they differ in objectives, timing, and methodology, they complement each other and share the common goal of ensuring product safety and efficacy. By implementing these processes appropriately, development efficiency improves, regulatory compliance becomes easier to achieve, and ultimately, better products can be provided to patients and healthcare professionals. Those engaged in medical device development should understand the differences between these two processes and strive to leverage their respective characteristics in their development approach. Particularly, integrating international standards such as ISO 14971 (risk management) and IEC 62304 (software lifecycle) with design control processes and building a consistent development strategy has become the key to success in the modern medical device regulatory environment.