Ex authorized person(s) in case you are a manufacturer

Top management shall ensure that the responsibilities and authorities for relevant roles are assigned, communicated and understood within the organization.
Top management shall assign the responsibility and authority for:
a) ensuring that the quality management system conforms to the requirements of this International Standard;
b) ensuring that the processes are delivering their intended outputs;
c) reporting on the performance of the quality management system and on opportunities for improvement, in particular to top management;
d) ensuring the promotion of customer focus throughout the organization;
e) ensuring that the integrity of the quality management system is maintained when changes to the quality management system are planned and implemented.

ISO 9001:2015 applies here with the following additions:
Ex authorized person(s) shall be appointed with defined and documented responsibilities and authority to ensure the following requirements are met:
a) the effective co-ordination of activities with respect to Ex Products;
b) the liaison with the issuer of the certificate (when not issued by the manufacturer) with respect to any proposed change to the design defined in the certificate and the technical documentation;
c) the liaison with the body responsible for the verification of the quality management system with respect to intended updating of the quality management system;
NOTE It is not practicable for the manufacturer to inform the body responsible for the verification of the quality management system each time the quality management system is updated. It is only practicable to inform them of “substantial” updating of the quality management system relevant to the type of protection.
Similarly, it is not practicable to specify in general terms what types of updating are or are not “substantial”. It is therefore normal that the manufacturer inform the body responsible for the verification of the quality management system on any update of the quality management system having consequences on Ex products compliance. The change of an Ex authorized person is considered as a “substantial” change.
d) the authorization of initial approval and changes to related drawings, where appropriate;
e) the authorization of concessions;
f) the accuracy of relevant information regarding Ex product given to the customer for any sales literature and installation instructions (which shall include applicable Specific Conditions of Use and any Schedule of Limitations);
NOTE Certificate numbers with a suffix X contain Specific Conditions of Use. Ex Component certificates numbers, with a suffix U contain a Schedule of Limitations.
g) the effective coordination of manufacturing processes related to Ex Products including externally provided products, services and processes; In the case of a manufacturer with multiple manufacturing sites an Ex authorized person with relevant responsibilities shall be appointed for each site.
Records demonstrating this shall be available and be maintained as documented information.
Not any is within your organisation, pls define one immediately. If there is one or more, pls keep their Ex knowledge updated.
Keep up good work!