Not all design inputs are necessarily related to some performance output. For some requirements such as color or force, there is an output that can be related to manufacturing or test related value. For some inputs such as ones based for end user validation such as "device works as intended" or "surgeon is able to manipulate instrument with ease", the validation of the device is binary which is either a yes or no. There is no output as there isn't a specific color, force, or rationale for the input that is chosen based on whim of the end user. 

All inputs have outputs, but I believe your confusion may be arising from the document name. There is an input document, an output document, and a design specification document (DSD). From my understanding, the input and output documents are the two parts that come together to form an additional document: the DSD. A company can omit the output document because the outputs are included in the DSD. It is a bit redundant to include each input and output twice, but I believe the DSD provides a convenience to the reader so that each variable is in one location.

I agree that although there isn’t a document that explicitly states a design output, it doesn’t mean that the design doesn’t have an output. The design input provides a general overview of what your product will look like and how it will function. The design specification gives the specifications of what exactly those inputs that the user or customer required—for example, the example that Dr. Simon has given was with the knob: red would be your input and a specific dye of red would be your specifications. There are also the design verifications that confirm that the output of your design meets whatever was stated in your design inputs. So, although there isn’t a specific design output document, your end product is being tested and documented to ensure they meet design input and specifications.  

You are correct in the sense that every input in the design control process should have an output. However, some companies do not and one of the reasons could be because of the simplistic nature of the medical device at hand. For instance, let's take a digital thermometer as an example. The DID for this device could be accuracy and user interface requirements but the DOD is simply a reiteration of the input requirements such as the quality control procedures used that were dependent on the input arguments. However, if a more complicated medical device was at hand, then a clear distinction between the input and output requirements would be expected. 

As a student delving into the realm of medical device development, I've come to appreciate the pivotal role played by Design Controls in guaranteeing the safety and effectiveness of these devices. Design Controls encompass a meticulously structured set of procedures that guide the design process, from initial planning to manufacturing transfer. These activities encompass understanding user needs, regulatory requirements, gathering crucial design information, creating detailed designs, ensuring compliance through reviews, testing for verification, validating in real-world scenarios, and ensuring a smooth transition to manufacturing. The significance of Design Controls is manifold. They act as safeguards, identifying and mitigating potential design risks, preventing the introduction of medical devices that might pose safety or effectiveness concerns to patients. Furthermore, they serve as a cornerstone for regulatory compliance, with agencies like the FDA stipulating their implementation, enabling manufacturers to navigate the complex regulatory landscape. Importantly, they contribute to improving product quality, as they systematically guide the design and testing process, facilitating the early detection and rectification of design flaws, ultimately resulting in elevated product quality and cost savings. In summary, Design Controls are an indispensable facet of the medical device development journey, providing a structured framework for managing the design process, ensuring both safety and regulatory adherence, and serving as a fundamental knowledge base for students venturing into this field.

In the context of design control, it is indeed common for companies to have a Design Input Document (DID) while not all have a corresponding Design Output Document (DOD). This discrepancy happens in scenarios where the design inputs are clearly defined based on the user needs, regulatory requirements, or safety standards, whereas the outputs may not be formally documented due to the nature of the product or the company's processes.

A good example of this would be when a company is developing a software application for internal use within the organization. The DID may include inputs such as user requirements, performance specifications, and compliance with internal security protocols, but since the software is not being produced for commercial sale, the company might not create a formal DOD. Instead, the output could be managed informally through agile methodologies where iterations and updates are documented in project management tools rather than as standalone documents.

In this case, while there are design outputs in terms of functional software features and updates, they may not be documented in a traditional sense as would be required for regulated products like medical devices. This approach can lead to ambiguity regarding what was implemented versus what was initially specified in the DID, displaying the importance of clarity and communication within the development team.

Great point! It makes sense that every design input should ideally have a corresponding output. Inputs set the foundation—they’re the requirements a device has to meet. In a perfect world, each input would lead to a specific output showing how that requirement was met in the design.

But sometimes, it doesn’t work that way. For example, general inputs like user needs or industry standards might not produce a concrete output right away. User feedback might shape overall features, but it could take a few design rounds before you see a finalized component or feature.

On that note, how do you see traceability fitting in here? Tracking how each input links to an output could help make things clearer. Curious to hear your thoughts on how companies might use traceability to connect those dots better!

I do not think of it as input-output relationship, especially for design purpose. Therefore, I don't think we need an output in this case. For design control, I think of input as standard and bullet points of what are considered for the whole project, not something to be processed, which means that they do not generate output per say. Even when there are output produced, they may get implicitly reported and handled, put back into the feedback loop. 

Hi hodafattel,
You are right in saying that inputs usually have outputs, but not always directly. For instance, a DID might specify user needs like "easy to use" or "durable," which aren’t standalone outputs but guide multiple outputs . In these cases, outputs might be spread across various documents rather than having a single, direct "Design Output" document.

Companies will have Design Input and Design Specification documents in their DHF. They might not have a Design output because the Design specification might already outline the outputs. In some cases, the device output might not be available until after successful validation. If the input includes costumer approval, they need to complete a validation process to access their design outputs.