As the market grows at a compound annual growth rate of over four percent up to 2020, line maintenance, an integral part of airlines' daily task is moving away from in-house to being outsourced globally. Creating efficiencies within line maintenance is imperative to the industry with aircraft checks regularly conducted on the tarmac in between flight operations to ensure airworthiness. Andrew Smith, Principal at Arthur D. Little is quoted as saying, "Changes in foreign ownership rules that pertain to airlines and their subsidiaries may have contributed to the growing tendency of airlines to outsource their maintenance activities to third-party providers."