Herman began his career in 1982 as a rotating equipment engineer at Prudhoe Bay, Alaska, with Sohio Alaska Petroleum Company.  In 1987, he transferred to refining and worked in numerous operations, maintenance, turnaround, project management, technical support, and refining management roles for BP, Tosco, Premcor and ConocoPhillips. 

Herman has worked directly with several refineries across the U.S. and Europe.  He was named refinery manager of the Bayway refinery in 2002.  In 2005, Herman became the general manager, Refining Business Improvement, and in 2008, he was named president, Refining, Marketing, and Transportation-Europe.  Herman began his current role in 2010.

Herman is a past board member of the Northwest Construction Consumers Council; Europia, the European petroleum industry association; and CONCAWE, the European consortium for health, safety and environmental issues in the petroleum industry.