Rob Packard The FDA recommends that you "close" your DHF when you receive regulatory approval of a product. The reason for this is that you want to know what inputs, outputs and V&V testing applied to the last "approved" product. Any subsequent changes are a "letter to file." I personally like to document these changes in the DMR by controlling the DMR as a controlled document. I also use a DMR Index. Therefore, the revision history at the bottom of the DMR index identifies each engineering change notice that has been made since the DHF was closed. I also use the DMR Index as a Technical File Index so I have one controlled document meeting two requirements. This revision history also meets all the requirements for maintaining a Class III Technical File under the new EU Medical Device Regulations. There are several other great ways to do this--including a DHF Index.

Maya Siboni Melamed The design change include all chages you perform in the product. If the input is changed you need to update the outputs and perform v&v to the changes.
Sometime the input doesn't change but the output changes for example following nonconformance or design improvement.
For each change we perform we have an ECO

Maya Siboni Melamed Changes on each design input and output shall be documented in ECO. We have a checklist in the ECO form to evaluate the impact of the change. If you change a screw you change the configuration of the product (BOM, drawing act are impacted) and you shall issue an ECO. In the ECO you shall evaluate if there is impact on the DHF documents and if V&v is required.

Hyemi Shin (신혜미,차장) Robert Packard Hi Rob, Thanks for your advice. It helps. Could you be more specific to my additional question: I wanted to know "What needs to be documented for design changes." Does the "letter to file" may include ECR, DMR and ECN only which is the result from the changes or must include design input, output, verification and validation as well like the initial DHF? For instane, the customer wants us to add different type of screw with same intended use and slightly different function. Then do I need to create design input file describing those differences? If my question is vague, please let me know. Thanks again!

Great advice, Robert!

G M Butcher The design changes must go through the same process as the original design. The concern arises when a change is planned that will require reporting. There is an FDA guide document that helps explain when to report a change. The risk exercise is very important at this step in helping to make the decision.

Al Christie As discussed by others, ALL aspects of the product need to be controlled in the DHF. I would expect to see controlled engineering drawings for the screws, etc as specifications which get up-revved under change management (your ECO, ECN, or other change note mechanism).

When transferred into production, as also mentioned above, the DMR comprising everything needed to reproduce that version of product will also be versioned. That will include the DHF docs at relevant issue, specs, bill of materials (BOM), etc.
Any changes to the product post design freeze or post market will update the relevant specs, v&v, and DMR. Certainly a note to file is required in all cases under design control, and you must consider the significance of the change to determine if FDA or other regulators must be informed, or if further steps (such as new 510k) are required. There are links on FDA website on how to consider significance if change. In EU you can discuss with your Notified Body.

In general, you must always ask can the change impact on safety and performance.

Markus Angst Every design change will invalidate at least one verification or validation item of the existing design. As part of the engineering change order, the re-verification and re-validation has to be identified and planned. This planning will result in a time and money budget, which could be relevant for the decision whether to execute the change. Once the change is approved, the DHF will be reconstructed from the lowest level item of re-verification (I call this "onset point") up to - if applicable - re-registration / re-certification of the product with the regulatory authorities.

Hyemi Shin (신혜미,차장) Hello all, It seems strange that I replied on the posting but it is not updated. Anyways, I really appreciate your valuable comments. It really helps a lot. Now I got an idea how to control design changes. Thank you!

Hyemi Shin (신혜미,차장) Thanks all for the valuable comments and advices. Your opinions are all very helpful to understand design change process and the important points to consider. I learned a lot really appreciated!! -Hyemi-