This document describes a methodology for designing dither signals to improve closed-loop system identification of industrial models. It formulates the dither signal design as an optimization problem (DSDP) that determines signal amplitudes to maximize excitation within input/output constraints. The DSDP can be solved in the physical or transformed space, and accounts for process gain information to better excite ill-conditioned processes. The designed dither signals are intended to provide data for updating existing industrial models used for control, optimization, and monitoring.