In designing analog integrated circuits, the step of selecting device sizes and biases is crucial to enhance the final performance, power, and yield of the circuits. In manual design flows, the designer first selects bias voltaje and branch current values, and then converts to widths and lengths via first-order equations. This is the operating-point driven (OP) formulation. Using OP makes it easy for the designer to maintain insight of the effect of design variables (voltage, currents) on performance, in addition to simplifying the sizing problem. In contrast to manual, automated sizing approaches in the computer-aided design (CAD) literature predominantly manipulate device sises directly. While simpler from a CAD perspective, the directsizing approach misses the benefits of OP—insight and a simpler problem that would lead to faster convergence and better results. We believe that the OP formulation is underused, because of lack of familiarity, inconvenience, and underappreciation of its benefits. This investigation aims to resolve that and help to improve CAD practice, by reviewing the literature on OP that has been accumulated over the decades, and describing the variants, applications, and benefits of OP.