The world’s electric power grids have evolved over the last 120 years from a single power line to today’s large networks. The evolution will continue at an accelerated rate with extensive smart grid development worldwide. For example, the U.S. government has set a goal of reaching 100% carbon pollution-free electricity by 2035, while the U.S. Department of Energy shared a goal to deploy 30 and 110 GW of offshore wind by 2030 and 2050, respectively. To meet such ambitious goals, a significant percentage of electricity will come from intermittent renewable sources and be supplied to a vast number of loads that will actively respond to grid conditions and incentive signals. This development is largely driven by environmental and economic factors, such as reducing carbon emissions and reducing electricity costs for consumers. These energy resources and responsive loads lead to new uncertain behaviors and dynamics that the grid has never seen and that were not considered in its design. Operating such a dynamic grid with sufficient reliability and efficiency is a monumental challenge. <xref ref-type="fig" rid="fig1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Figure 1</xref> presents three challenges faced by software tools used in power systems planning and operation along with solutions.