Greg worked with Vipac Engineers as a software engineer specialising in complex systems integration. He then joined ADI to establish their defence software division to service the Frigate construction programme. This work is highly classified but the Thales joint venture subsequently appointed him GM for their Asian air traffic control operations. He was recruited to the position of MD Australian Submarine Corporation in 2004 to manage the construction of the Air Warfare Destroyers ? a $5 billion programme. The ASC is also responsible for the through life maintenance of the Collins Class submarines. He is thus supervising the largest marine defence operation in the southern hemisphere incorporating state of the art marine engineering and defence software systems integrating with American and European suppliers and Navies.