Bob Bunker, chairman of Medical Staffing Network, worked to optimize internal operations since joining the company in 2011. He consolidated several operating systems, fostered MSN’s corporate culture and launched the company’s workforce management solutions and case management businesses. Prior to joining MSN, Bunker was chairman, president and CEO of Hospital Physician Partners, Aperture Credentialing and Medical Services Company; chairman of Omniflight Health Services; and COO of Humana Military Healthcare Services and Humana’s commercial nationwide Medicare and Medicaid programs. MSN is the sixth-largest U.S. healthcare staffing firms and 54th on the list that includes all staffing categories.