FDA, Experts Weigh In on Industry Troubles with Design Input, Output Activities
Not enough device manufacturers use design review as a mechanism to make sure that design input and output activities are done properly, FDA says.
“Firms have available to them the very valuable tool of design review within their quality management systems,” said Jan Welch, Deputy Director of Regulatory Affairs in CDRH’s Office of Compliance. “To the extent that design inputs are inappropriate, unachievable, poorly characterized or not documented, the design review process should identify these concerns and flag them for resolution prior to the next design steps. The same holds true for design outputs.”
Design review – a documented, systematic examination of a product design to evaluate whether it meets user requirements – is required by Quality System Regulation 21 CFR 820.30(e) as part of the design control subsection.
Design inputs – the cornerstone of product design – establish device requirements relating to function, safety, design and performance. Meanwhile, design outputs are reviewed to ensure that input requirements have been met or addressed.
“If issues with design inputs and outputs remain unaddressed throughout the design process,” Welch said, “the firm likely has underutilized its design review mechanism.”
The QSR does not prescribe how often design reviews should be performed; it is left up to companies to decide. Design review results are documented in design history files. During an FDA inspection, “investigators often see issues with design inputs and outputs when reviewing and assessing design review results found in design history files,” Welch said.
FDA: Design Input, Output Activities Not Documented by Manufacturers
Another serious problem FDA investigators see is firms failing to properly document design input and output activities.
“Manufacturers must have the necessary documentation to demonstrate that design inputs for their device adequately address the intended use … and the needs of the user and/or patient, including risk assessment and human factors considerations,” FDA’s Welch said.
When it comes to “design outputs, manufacturers need to have enough documentation to show that design outputs match the requirements of the design inputs,” she said.
Manufacturers sometimes wonder how much design input and output documentation will satisfy the agency.
John Avellanet, Managing Director for Williamsburg, Virginia lean compliance consulting firm Cerulean Associates LLC, said agency investigators will scour a company’s desiggn history files to ensure that every design input is traceable to an output.
For an investigator, “it’s really a process of reviewing the documentation and being able to reconstruct design decisions vis-a-vis the finished device,” he told The Silver Sheet on June 5th. “If there is enough information to satisfy that, then the firm has adequate documentation from FDA’s perspective.”
When firms ask themselves how much documentation they need for design inputs and outputs, the answer that is typically given by FDA is “something along the lines of ‘Enough to ensure the quality, safety and effectiveness of the device.’ Sadly, this is not a practical answer that allows you to go forth and decide.” Avellanet said. “What is enough documentation and detail to ensure the safety and effectiveness of a device? The person who is a perfectionist will have far more documentation and detail than the person who believes that ‘good enough is good enough.'”
Avellanet advised, “Step back and look to the end. What are the goals of the design input and design output documentation? To sit in your files with someone’s approval signature on them awaiting FDA review?”
“If we really think about our needs are in terms of design input and output records, we need design inputs and outputs to be usable and defensible. We need to use them to actually design and make the device. We need to be able to use these same records to defend any accusation by FDA that our device is unsafe or ineffective. And we need to use those same records to defend patent scrutiny. And we’ll need them to defend against the inevitable medical product liability litigation.”
Avellanet explained that with his clients, “I find that we can create a core set of defensible documents for design input and design output records by using four tools:
- design input review checklist
- design output review checklist
- the GHTF’s summary technical document (STED), and
- a simple requirements table or matrix (into which you put all the inputs and outputs together, then make sure there are no blank fields).
So, think about the design input review checklist. Just to identify a few points, use the design input review checklist to verify you have documented:
- intended use or indications for use
- human factors requirements
- functional requirements
- material biocompatibility requirements
- shelf life specifications
- durability requirements
Each of these should then be traceable to a documented decision or a report or a memo or a research finding, etc. that is maintained or otherwise referenced in the design history file. The key is to use the checklists as a summary of proof that you conducted the design input and design output activities, and have enough documentation necessary to satisfy FDA and protect yourself against the investigator and the litigator.”
Then, during design review, suggested Avellanet, use the completed checklists as one element during the review. This “closes the loop” while keeping overall design controls streamlined.Excerpted from original June 2012 publication in “The Silver Sheet”