The presentation will focus on practical aspects of commissioning control loops in commercial HVAC systems and evaluating their routine performance. Simple and theoretically sound methods for diagnosing control performance will be presented that detect serious performance issues associated with control loops in modern buildings. The discussion will center on a new control loop commissioning tool that helps field personnel to quickly test, tune and troubleshoot control loops. In addition to the active tests for commissioning control loops, a suite of diagnostic algorithms are used in a finite state machine framework for observing routine loop behavior and characterizing its control performance under stochastic and load disturbances, setpoint changes, oscillatory behavior as well as detect out-of-control situations. The above mentioned ideas are implemented in the Matlab environment and tested both in an emulated environment (hardware-in-the-loop) as well as on real building control systems. Experience in implementing research ideas on real systems using Matlab graphical user-interface development environment as well as rapid prototyping tools such as Matlab Real-Time Workshop and LabView RealTime with distributed I/O will be discussed. The use of these automated software tools significantly cuts down the concept to production lag time and reduces the code interpretation/translation errors to virtually zero.