Department of Homeland Security 'Office of Inspector General' Budget Overview (Fiscal Year 2018 Congressional Justification) [open pdf - 309KB]
From the Component Overview: "The Office of Inspector General (OIG) is comprised of the following mission-oriented programs that support achievement of the DHS strategic missions, goals, and objectives.  'Mission Support': The Mission Support program provides enterprise leadership, management, and business administrative services that sustain the day-to-day back office operations. Key capabilities include managing the agency's performance, finances, workforce, physical and personnel security, acquisition of goods and services, information technology, property and assets, communications, legal affairs, and administration."
U.S. Department of Homeland Security: https://www.dhs.gov/