Sterile processing departments (SPDs) clean and pack reusable surgical instruments. They directly affect productivity, efficiency, safety, and infection control within acute interventional care. About 15% of surgical instrument trays have missing, broken or dirty instruments, that can lead to surgical site infections and a range of safety, procedural, and inefficiency problems. Rather than being the fault of individuals, our prior funded R03 Work Systems Analysis demonstrated a range of performance-shaping factors and the need for staff and administrators to balance of multiple interacting system components and resources. We propose to extend or R03 work to develop interventions, improve data-analytic approaches, and predictive models, across multiple facilities. The overall aim is to harmonize the SPD work system to create optimized safety and quality, controlled production costs, and increased efficiency through systems modelling, interventions, data visualization, and prediction tools. Our first aim is to develop multiple system models of five sterile processing units across two hospital systems that will provide a comprehensive understanding of SPD system function, allow the comparison of methods for representing SPD work and the prediction and evaluation of interventions to improve point-of-use reprocessing, tray composition, and interruption management. Our second aim is to create data visualization tools that highlight systems interactions and thus enhance decisions making. Our third aim is to develop discrete event simulations that predict performance based on system parameters, providing a tool for making decisions and for understanding how decisions are made. This will be the biggest program of research in sterile processing ever conducted.