On-Call Security System Services - labor, tools, equipment, trucking, supervision, installation, repair, remedy, replacement, etc. 1) The Contractor must be a qualified, appropriately licensed by the Commonwealth in the field employed or the trade undertaken. The contractor must have a minimum of 8 years of experience in the subject trade for commercial clients, municipalities, institutions, and/or school districts. The contractor shall use only trained and licensed personnel to perform the services. 2) All Contractor personnel shall have a copy of all required certifications and licenses on their person when on duty in the City. All persons operating a motor vehicle on public ways or private property, and on City property must possess a current valid driver license to operate a motor vehicle. 3) The Contractor shall give supervision to the work and shall employ competent tradesman during the progress of the work. A Contractor shall utilize a sufficient number of competent workers who are experienced thoroughly in this type of work so as to progress to completion of work without unnecessary delay.