The most challenging part is that you have to be sure that you have designed your medical device according to all applicable requirements stated in Annex 1 – General safety and performance requirements. Following the requirements on that list will give you information on whether your product is well designed, manufactured and packaged, and whether you have proven the safety and effectiveness of your product with appropriate tests.
The next thing concerns the technical documentation. Technical documentation covered in Annex 2 is extensive but durable. Preparing the necessary applicable documentation takes time.
The third thing that is challenging is preparing the documentation for the quality management system. In Article 10 General obligations of the manufacturer, point 9, is stated which elements must be covered by the quality management system. This quality management system is based on ISO 13485:2016, but there are some more requirements in the MDR that also need to be part of the quality management system.
On the following link, you can see how we prepared the documentation toolkit for ISO 13485 to be in compliance with MDR requirements: