FDD (Fault Detection and Diagnostics)

FDD automates the process of detecting faults with physical systems and processes and diagnoses their potential causes. FDD systems for HVAC generally use a database of "expert rules" that analyzes BAS and meter data to determine fault conditions. FDD is a subset of EMIS, focused on system-level monitoring (using the BAS data), and it is sometimes referred to as a monitoring-based commissioning system.