OCA (One Config Advanced) and SSET (Solution Sizer and Estimator Tool) are both tools that help design and configure HPE solutions. OCA is a web-based tool that allows users to create and validate configurations for HPE servers, storage, and networking products. SSET is a tool that helps users estimate the power, cooling, and space requirements for HPE solutions. SSET also provides recommendations for rack and power distribution units (PDUs). Compared to OCA, SSET requires an additional datacenter characteristic to configure a solution: the input voltage. This is because the input voltage affects the power consumption and efficiency of the solution. The input voltage can be either single-phase or three-phase, and it can vary depending on the country and region. SSET allows users to select the input voltage from a list of predefined values or enter a custom value. OCA does not require the input voltage as an input parameter, as it only focuses on the product configuration and compatibility.Reference:Edge to Cloud Solutions: Engineered Experiences to Unlock Your Full Potential, Chapter 5: Next Generation Compute, Storage, and Integrated Data Solutions, page 97. HPE SSET User Guide, page 7.