Under the Machinery Directive 2006/42/EC when partly completed machinery is first placed on the market it will not be CE marked, but it must be accompanied by a Declaration of Incorporation instead of a Declaration of Conformity.
When placing on the market partly completed machinery, which are drive systems and other assemblies that are:
This is basically because partly completed machinery is not in a final state that will allow it to operate and it needs to be incorporated with other parts so it can work as part of the final machine. In its partly completed state it may be not be able to fully conform to all of the essential health and safety requirements of the Directive. The interface where partly completed machinery will be combined with other parts will therefore require assessment and protection when the final machine is assembled.
This legal status cannot be used as a means of avoiding the full conformity assessment required by the Machinery Directive for complete products (eg by leaving off safety items such as guards and saying it is "partly complete"). If a product can operate as a machine it must always be fully protected with all safeguards provided, be CE marked and accompanied by a Declaration of Conformity.
In addition to similar particulars as required on a Declaration of Conformity (manufacturer / authorised person details, description etc, date and signature, etc), the Declaration of Incorporation must also clearly state:
Part 2 of schedule 2 of the Supply of Machinery (Safety) Regulations 2008 details the full particulars that must be contained by a Declaration of Incorporation.
As the partly completed machine is clearly intended for incorporating with other partly completed machinery, or equipment, to form a machine (as the Declaration of Incorporate should state), you should not bring the final machine into use or place it on the market until it has been through the relevant conformity assessment process and made safe. The incorporation of partly complete machinery may require, for example, extra guarding at the interface for which you will be responsible.
The conformity assessment procedures for machinery are described in part 8 (self certification), 9 (EC type-examination) and 10 (full quality assurance) of schedule 2 to the Supply of Machinery (Safety) Regulations 2008. Only at their conclusion, when the final product is safe, and when you have issued a Declaration of Conformity and affixed the CE mark, can the final product be brought into use or placed on the market.
Partly completed machinery must come with instructions for incorporation, as well as a Declaration of Incorporation, and both these instructions and the Declaration of Incorporation should be included in the technical file for the final product. Although you are responsible for the safe incorporation of the partly complete machine, you are not responsible for the aspects of design covered by the Declaration of Incorporation. The final product's instructions may need to take account of the instructions for the partly completed machinery element, eg for maintenance of that component part.