Andrew spent 20 years as a Senior Vice President at RMS, after his startup company merged with RMS in 1998. After a period as Managing Director of RMS Europe, he moved to work at RMS headquarters in Newark, California, to help grow the business to become the leading catastrophe risk analytics company. He developed a number of RMS catastrophe risk models, including the RMS terrorism risk model, models for the risk of pandemics, excess mortality, longevity risk, and workers' compensation for injury in earthquakes.
From 2015 to 2018, he led the development of the RMS cyber risk model and developed exposure data monitoring standards for a dozen classes of insurance beyond property nat-cat.
On his retirement from full time work at RMS, his colleagues awarded him a t-shirt with the slogan '$309 million man' - an estimate of the total revenues earned by the products he designed.
In 2021 RMS was acquired by Moody's for $2bn.