(34)It is essential that, before drawing up the EU declaration of conformity or the EU declaration of incorporation, the manufacturer prepare technical documentation. The manufacturer should be required to make that technical documentation available to national authorities on request or to notified bodies in the context of the relevant conformity assessment procedure. Detailed plans of subassemblies used for the manufacture of the product within the scope of this Regulation should only be required as part of the technical documentation where knowledge of such plans is essential for assessing conformity with the essential health and safety requirements set out in this Regulation.