With over three decades of experience in the oil and gas industry, Andrew Mackenzie has made seismic changes since becoming CEO of BHP Billiton in 2013. Mackenzie started his career in science and won accolades as a postdoctoral research fellow for the British Geological Survey. His transition into the corporate world began with BP, after which he moved onto BHP Billiton’s biggest rival, Rio Tinto. Mackenzie is responsible for the simplification of BHP Billiton’s corporate structure, which freed it to make progress in focused areas. In 2014, the Royal Society recognised Mackenzie as one of the world’s most influential applied scientists.