Some of the biggest stumbling blocks encountered by medical device firms on the way to clearance or approval of their devices by the U.S. Food and Drug Administration (FDA) are related to design control.
This is the reason why in 1996, the FDA added design control principles to 21 CFR Part 820, also known as the Quality System Regulation (QSR). The revision required manufacturers of some Class I and all Class II and Class III devices to follow the conditions and parameters provided under Subpart C, Section 30 of 21 CFR Part 820. (www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?fr=820.30 ). The mandate added a whole new level of complexity to the already rigorous and challenging device development process.
In addition to designing and testing devices, development engineers must also ensure that all necessary documentation is in place to demonstrate design control. This amounts to hundreds if not thousands of documents for every single product launch.
Two decades after the Part 820 revision was published, design control remains a significant challenge for device manufacturers. Even after a manufacturer has successfully launched a medical device, it needs to maintain quality vigilance and comply with post-market requirements or risk regulatory violations.
According to the FDA’s latest statistics, 14 percent of Form 483 observations and warning-letter citations issued by the agency pertaining to Part 820 stemmed from problems with design control. That’s 515 out of a total of 3,740 observations and citations focusing on medical devices in 2014, as per the “2014 Annual FDA Medical Device Quality System Data,” presented by the Center of Devices and Radiological Health, and listed on the FDA.gov website.
Documentation Burden of Design Control
Under 21 CFR Part 820.30, there are nine elements of design control, each one requiring strict documentation. Let’s take a closer look at these elements, what the documentation burden of each means, and some tips for addressing the requirements. (See Figure 1)
Design and Development Planning or DDP: “Each manufacturer shall establish and maintain plans that describe or reference the design and development activities and define responsibility for implementation…The plans shall be reviewed, updated, and approved as design and development evolves.”
Tip #1: This requirement indicates that design control is intended to be a prospective activity in the development process. You must incorporate a planning period into your development process up front to ensure timely product launch and minimize your risk of product failure. A key part of DDP is assignment of tasks to responsible parties. Make sure your DDP process allows timely communication among those parties, such as providing automatic notification, follow-up, and escalation of tasks within your design control system.
DDP requires proper documentation with corresponding reviews and approvals. As your plan evolves, be sure your documentation is updated and each revision should be reviewed and approved.
Design Input: "Each manufacturer shall establish and maintain procedures to ensure that the design requirements relating to a device are appropriate and address the intended use of the device, including the needs of the user and patient...The design input requirements shall be documented and shall be reviewed and approved by a designated individual."
Tip #2: Many manufacturers mistakenly assume that user requirements gathered by their marketing teams are sufficient as design input requirements. It is a good starting point for developing design input, but it’s not enough because most of the time, that information is qualitative, and therefore, insufficient.
You need quantitative design input that can be easily measured. Good sources of design input include priorgeneration customer complaints, medical device reporting (MDR), service reports, corrective action and preventive action (CAPA), standards, sales feedback, marketing surveys, user conferences, journal publications, and competitor products. Once you have defined design input requirements, any changes must be implemented according to your change control procedures.
Design Output: “Each manufacturer shall establish and maintain procedures for defining and documenting design output in terms that allow an adequate evaluation of conformance to design input requirements…Design output shall be documented, reviewed, and approved before release. The approval, including the date and signature of the individual(s) approving the output, shall be documented.”
Tip #3: The design output refers to the completed device at the end of the development cycle, but it’s not limited to the finished device. Your design output should include all documentation during the development process verifying that the design input requirements were met—plus any item that serves as a basis for the finished device specifications. Based on common industry practice, you may use the design output of one phase as the design input for the next. The culmination of design output is the completed device master record (DMR) that fully specifies the device, its packaging, and labeling. Remember that any changes to the DMR are subject to formal change control per the QSR.
Design Review: “Each manufacturer shall establish and maintain procedures to ensure that formal documented reviews of the design results are planned and conducted at appropriate stages of the device’s design development… The results of a design review, including identification of the design, the date, and the individual(s) performing the review, shall be documented in the design history file (the DHF).”
Tip #4: Design reviews, which are crucial to the efficacy of the design control, should be planned for up front in the DDP because changes late in the design cycle are more costly than those made early on. You can avoid expensive nonoptimal redesigns close to the launch date by conducting design reviews—and identifying changes—sooner rather than later.
The QSR specifies that you need an independent reviewer. Choose a person who is far removed from the design so as to provide an objective review, but at the same time possesses the necessary qualifications to provide meaningful feedback.
Design Verification: “Each manufacturer shall establish and maintain procedures for verifying the device design… The results of the design verification, including identification of the design, method(s), the date, and the individual(s) performing the verification, shall be documented in the DHF.”
Tip #5: Compare your design output with your design input to determine if design requirements were met. There are many forms of design verification. Risk analysis is part of design verification and will commonly take the form of Failure Modes and Effects Analysis (Design FMEA). Other common forms of design verification include benchtop tests and quality analysis. A good design trace matrix (a table in which design inputs are matched with design outputs) is particularly effective as a design-verification tool. The ultimate goal of this step is to verify that the design output meets the engineering specifications that were derived from the user needs.
Design Validation: “Each manufacturer shall establish and maintain procedures for validating the device design… The results of the design validation, including identification of the design, method(s), the date, and the individual(s) performing the validation, shall be documented in the DHF.”
Tip #6: Take note that design verification precedes design validation and is not a substitute for the latter. QSR requires validation testing to be conducted on actual production units or their equivalents. When using equivalents, you must provide documentation that clearly demonstrates the equality. Don’t manufacture test units under special conditions that don’t mimic actual production. For example, don’t let an engineer perform the final assembly when the job would normally be performed by a manufacturing operator, because an engineer’s skill level and knowledge base are likely to be very different from those of an operator. This step is intended to validate that the engineering specifications were translated properly from the user needs and thus the design output does indeed meet the user need defined in the design-input phase.
Design Transfer: “Each manufacturer shall establish and maintain procedures to ensure that the device design is correctly translated into production specifications.”
Tip #7: At minimum, the design transfer process must assess the completeness and correctness of the production specifications. Furthermore, the specifications must be reviewed and approved, and placed under the formal change control process. Most of all, you must make sure that the product is manufactured only to the latest approved revision of the DMR.
Design Changes: “Each manufacturer shall establish and maintain procedures for the identification, documentation, validation, or where appropriate, verification, review, and approval of design changes before their implementation.”
Tip #8: After you have finalized and approved the design input requirements, any changes are subject to formal change control process. Once you have verified and validated the design output specifications, any changes will also require change control. This entails documentation and evaluation of every design change, although it doesn’t mean every single change requires the same level of scrutiny.
Design History File: “Each manufacturer shall establish and maintain a DHF for each type of device. The DHF shall contain or reference the records necessary to demonstrate that the design was developed in accordance with the approved design plan and the requirements of this part.”
Tip #9: The DHF is intended to serve as the repository of documentation generated by the design control process, with each of the elements discussed above contributing documents to the DHF. Make sure you assemble your DHF properly because it will be referenced throughout the life of the product. The DHF is crucial when a question arises about the design’s integrity long after a product has been launched. A manufacturer could pay a high price for an inadequate DHF if such a question leads to a recall of several years’ worth of product. (See Figure 2)
Leverage Design Control
Design control is meant to help you develop and manufacture safe and effective products that readily comply with regulations. If you leverage the nine elements discussed above, they will help you focus on building your core competency, instead of just fulfilling regulatory requirements.
Given the voluminous documents generated by design control, you will greatly reduce your burden by establishing an integrated quality management system (QMS) that connects your design control procedures with your quality processes (such as CAPA, customer complaints, and change control), as well as your enterprise resource planning system. Such integration will ensure the smooth transfer from design to manufacturing and easy access by the design team to CAPA, customer complaints, and other qualityevents information necessary for implementation of design input requirements.
If your company uses a paper or hybrid (partially electronic and paper) QMS, switching to a fully automated system will be a significant step toward reducing the documentation burden of design control. By automating repetitive tasks such as routing, follow-up, collaboration, escalation, and review and approval, you will significantly cut the time and effort involved in managing design control. Automation will also standardize and streamline your design control procedures, making it easier for your stakeholders to participate in compliance efforts. All of these will help you increase efficiency, optimize productivity, and accelerate time to market.
This article was written by Matthew M. Lowe, Executive Vice President at MasterControl Inc., Salt Lake City, UT. For more information, Click Here .