In my opinion, the tech file/dossier is more useful. The reason being is that it gives an overview to the entire product and design and is most useful to someone that was not heavily involved in the device’s development. This is most useful when device failures come to light for someone that was not directly involved in the project but is responsible for rectifying the issue. It can also be helpful for someone who worked on the product but cannot recall all of the details due to a passage of time. It also holds of the documents to meet essential requirements, which is most useful during an audit.
Once instance that I can think of that a DHF would be more useful is during the development stage of a similar product. For example, if a new syringe containing a hormone supplement, with a dose of 100-microliters, is being developed and previously, a similar product with a dose of 50-microliters was developed, a DHF of the 50-microliter dose would be most useful because things like packaging, labeling, storage, etc. can be used as a starting point for the new, 100-microliter product. If a similar approach is being used to develop the 100-microliter syringe, a team could avoid the failures and obstacles that were already previously explored while developing the 50-microliter syringe.
-Michelle F