Researchers conducted a study to propose new approaches for determining staffing needs in the U.S. Secret Services highest-priority administrative, professional, and technical functions. They used objective and subjective, quantitative and qualitative methods to create staffing models. The authors applied a bottom-up approach commonly used for staffing models of administrative work that involved constructing process maps for the major work processes that produce each functions outputs and pairing those maps with estimates of the frequency and duration of each process. These bottom-up inputs let them estimate the total workload to calculate an actionable number of full-time-equivalent employees that will be sufficient to accomplish the functions workload. They also discuss the more subjective approach of business-case analysis, which was occasionally helpful in generating supplemental information or that they used for areas in which the work was too unstructured for the bottom-up approach to yield reliable estimates. This report documents the teams methods, implementation considerations, and lessons learned for future workforce studies.