Infrared mosaic focal plane arrays (MFPA) are complex integrated microelectronic devices whose operation is based on a large number of voltages in which the performance is very sensitive to voltage variations. Due to chip-to-chip variations, a computer-based system and a systematic procedure for efficient individual optimization of these operating voltages is essential. At present, the feedback or control in the loop is handled manually, but the system development is oriented toward a transition to automated control once sufficient understanding of the optimization procedure is gained. A fundamental premise of this optimization procedure is that the MFPA performance data is processed in near real-time and displayed in a concise and vivid manner, thus facilitating quick, easy, and confident interpretation. In the Mosaic Sensor Test and Calibration (MOSTAC) facility at the Lockheed Palo Alto Research Laboratory, a summary page output is immediately presented along with visual display of the spatial distribution of the signal, noise, and signal-to-noise. The procedure has generally consisted of (1) coarse optimization by determining the regions of good device responsivity and (2) fine optimization by minimizing the noise (while not losing the responsivity). This has allowed quick optimization of IR mosaic sensors with several MFPA chips in a single day. This paper describes the MOSTAC facility and how it is used to provide rapid optimization of MFPA performance with some specific examples on infrared charge-coupled imagers.