na moje wyczucie, z poniższych linków wynika, że “discipline engineer” to po prostu ichnie określenie naszego “specjalisty ds…” - z tytułem inżyniera – z danej branży/specjalności; w tym konkretnym wypadku chodzi o budowlańca, ale termin funkcjonuje też w wielu innych branżach

http://www.iacsltd.co.uk/vacancies.html
http://www.dsurveys.com/faq.html

Mechanical Completion Certificate (MCC) - A certificate issued per discipline by the executor to document that his MC scope is completed. On major projects, the MCC certificate is normally verified by the responsible discipline engineer within the company’s commissioning team or a nominated person within the project completion team, e.g. when performing mechanical completion verification at suppliers. http://www.docstream.no/ppcon/5067/Completion Manual_1_for_P...

(...) A discipline engineer(s) develops the criteria for his or her discipline in accordance with user
requirements and applicable documents. After completion of the criteria, the discipline engineer(s) will
check his or her work to ensure completeness and that user requirements have been met. http://www.hnd.usace.army.mil/engrdir/qual-mgmt/manual.pdf