GAB Robins North America Inc. has opened an office in Burbank, the company’s second in the San Fernando Valley. GAB, a risk management services firm handling claims administration, managed care and antifraud services for self-insured groups, said the new office reflects the increased needs due to Workers’ Compensation and other programs in California. The company’s other Valley office is in Glendale and GAB also has a Palmdale location. The Parsippany, N.J.-based company maintains more than 330 offices nationwide.