DHF, DMR, DHR Process, Part 2 – DMR->DMR

Posted by Bob Duffy on October 17, 2017 in Device Tips, Manufacturing

Design History File, Device History Records, Device Master Record, Device Tips, DHF, DHR, DMR

This is the 2^nd of the 4-part series around tips for leveraging the interrelationship between the Design History File (DHF), Device Master Record (DMR) and Device History Records (DHR’s). This tip is focused on creating the Device Master Record (DMR) from portions of the Design History File (DHF), with additional elements, typically from Manufacturing, Quality Assurance and Marketing.

In the previous Device Tip, I mentioned that the records of the design and development of a Medical Device are kept in a Design History File (DHF) during development prior to commercial release. I like to think of the DHF as the records of the Design Control process.

Now we get to the DMR. FDA defines the DMR as “a compilation of records containing the procedures and specifications for a finished device”. I like to think of the DMR as the recipe for a specific finished device. More specifically, the DMR typically must contain the following elements:

• Device specifications including appropriate drawings, composition, formulation, component specifications, and software specifications;
• Production process specifications including the appropriate equipment specifications, production methods, production procedures, and production environment specifications;
• Quality assurance procedures and specifications including acceptance criteria and the quality assurance equipment to be used;
• Packaging and labeling specifications, including methods and processes used; and
• Installation, maintenance, and servicing procedures and methods.

In the previous Device Tip, I recommended creating a matrix that links elements of the DHF, DMR and DHR. So here’s the next tip:

At the beginning of design and development when the DHF is started, identify those elements of the Design History File that will be transferred to formal Document Control and become the Device Master Record (DMR).

This will take one more task away from the typical end-of-the-project crunch. This will also allow input from Manufacturing, Quality Assurance and Marketing as appropriate, throughout the design and development process. It is also likely that these groups will also use these elements to create some of the other elements they typically create, such as production procedures, Quality assurance procedures and labeling (including Instructions for Use or User Manuals).

More Info on DMR

I like to think of the DMR as the “recipe” for the device. For example, the “DMR” could be the recipe for a cake (obviously not a Medical device, but this is just an illustration), for a bakery that makes and sells cakes for a living:

• the “Device specifications” would include the list of ingredients and amounts, and specifications for each ingredient;
• the “Production process specifications” would include the step by step instructions for combining the ingredients, the equipment (i.e. a mixer or an oven), methods (i.e. stirring, whipping, sifting, baking), tools and fixtures (i.e. spoons and mixing bowls) and the environmental specifications under which they are combined;
• the “Quality assurance procedures and specifications” would include homogeneity of mixed ingredients, taste, appearance, etc. and any equipment to be used for these determinations;
• the “Packaging and labeling specifications” would include the packaging box, box closure items, and any labeling on the box or closure items; and
• obviously bakery cakes don’t get installed, maintained, or serviced, since they’re typically one-time use products. However, even one-time use products typically include environmental conditions for storage prior to use (i.e. the cakes might require refrigeration). Devices that are installed, maintained, or serviced would need Installation, maintenance, and servicing procedures and methods in the DMR, typically in the form of an Installation Manual and Service Manual.

At the completion of development, only a portion of the Design History File is transferred to formal Document Control and becomes the Device Master Record (DMR) to be used by manufacturing to produce devices for commercial distribution.

Typically the DHF contains at least the following elements:

1. Design and Development Planning – design and development plans
2. *Design Input – requirements and specifications
3. *Design Output – electronic, mechanical, software, packaging and labeling designs
4. Design Review – design review records
5. Design Verification – design verification protocols and reports
6. Design Validation – design validation protocols and reports
7. *Design Transfer – design output translated into production documents
8. Design Changes – identification** or design changes

**NOTE: the other elements of design changes are captured in the other sections of the DHF.

The items indicated with an asterisk (*) are the only elements of the DHF that typically become part of the DMR.

Of the total content of a DMR, only Device specifications and Packaging and labeling specifications typically come from the DHF. The majority of Device specifications come from the Design Output of the DHF and typically include:

1. Electronic Design Output,
2. Mechanical Design Output, and
3. Software Design Output

However, only a relatively small portion of the total Design Output in these areas goes into the DMR, that is, only that portion of the Design Output needed to manufacture the Finished Device. So for instance, say the device has a Printed Circuit Board assembly that has the following Design Output:

1. Electronic Hardware Specification
2. Hardware Block Diagram
3. Hardware-Software Interface Specification
4. PCBA Specification
5. PCBA Theory of Operation
6. Schematic Design File
7. PCB Design Files
8. PCB Fabrication Files (Gerbers)
9. PCB Fabrication drawing(s)
10. PCB Assembly drawing(s)
11. PCB Bill(s) of Material
12. Electronic Component Specification(s)

Design Note(s)

To build the PCBA in manufacturing only requires:

1. PCB Fabrication Files (Gerbers)
2. PCB Fabrication drawing(s)
3. PCB Assembly drawing(s)
4. PCB Bill(s) of Material
5. Electronic Component Specification(s)

So for a PCBA, the DHF-DMR matrix would look like this:

The rest of the DHF-DMR matrix can be put together similarly, to include all elements of the DHF that will become part of the DMR.

In the next Device Tip, I’ll discuss completion of the DMR.