Design Outputs – Truly Control Your Design
By Mark Foley – Sr. Mechanical Designer
If you are involved in the development of medical devices, it’s likely you’ve heard the words ‘design outputs’. Well – What are design outputs? What purpose do they serve? Why should I be concerned about them? These are all just a few questions you will probably ask yourself. I once asked myself the very same questions. After spending the better part of the last seventeen years in medical device product development, I hope that I can help explain what is often a widely misunderstood part of the process.
I’m sure it’s no surprise that referring to the FDA-regulated process for medical device development known as design controls. The design controls process provides a development workflow and a set of criteria of which the FDA expects medical devices under development to conform to if a company hopes to receive approval to market their device in the U.S.
Design outputs are the work produced at the end of design effort, such as drawings, material specifications or manufacturing instructions. They are what controls your design. They must also meet design inputs criteria defined in the planning stage of your project during design verification.
I often see little time spent thinking about how design outputs will be verified until after the close of the design effort and the start of the verification stage. By this time, it’s too late; it’s something that needs to be considered right from the start of design inputs at the beginning of your work. You will end up wasting time making updates to outputs that have already been released but don’t provide the information you need to verify their inputs. You will find yourself having to navigate the change control process in a hurry as you try to keep the project on schedule. I’ve seen projects delayed for months because of things like this. This scenario can be avoided by paying a little more attention to the design outputs and ensuring they contain the information to make verification possible.
I recommend that during your design stage you create a mechanism to serve as a deliverable that will force you to evaluate each design output against each design input before its release. This is a paper exercise that can often be accomplished in a single document. I like to refer to the document as a technical review. In this document, capture your input and the acceptance criteria that you will use in verification, checking that the information or specification is contained in your design output. Time spent performing this exercise before closing your design stage and freezing your design will serve you well.
Changes made after a design freeze can often mean that other activities or assessments will need to happen and these activities are sure to drain time from your schedule and money from your budget, which doesn’t do anyone any good.