The Improving Modular Patient Admission Capacity Through Scalable Solutions (IMPACTS) Project, implemented by the University of California, Davis, is funded under the National Disaster Medical System (NDMS) Modular/Convertible Capability Pilot under the direction of the Defense Health Agency (DHA) as the technical and administrative sponsor. The project has developed and sourced a modular, scalable, joint military-civilian patient care facility, referred to as the Modular Surge Facility (MSF), which may be utilized to quickly expand hospital inpatient capacity during patient surge events. During mass casualty and patient surge events, healthcare systems must efficiently manage bed capacity, triage effectiveness, and resource allocation. Additionally, they must rapidly scale patient admissions to meet increasing demand in order to prevent overcrowding, care delays, and system collapse. However, traditional hospital admission models often lack the predictive and adaptive capabilities needed to respond effectively to sudden patient influxes. The IMPACTS project intends to provide a decision tool (Patient Surge Tool) to managing hospitals to help determine how expansion of patient care capacity through the utilization of an MSF will affect hospital throughput and other operational metrics. This document describes the methodology behind this approach.