The IPACS project was funded by Health Data Research UK. It ran from May 2020-March 2023. The project was undertaken by a research team of six from Bristol, North Somerset, South Gloucestershire Integrated Care Board (BNSSG ICB) (Dr Richard Wood and Dr Paul Forte), University of Bath School of Management (Prof. Christos Vasilakis and Dr Zehra Onen Dumlu) and University of Exeter Medical School (Prof. Martin Pitt and Dr Alison Harper). The IPACS project aimed to investigate what might constitute 'optimal capacity' along different parts of the complex care discharge pathways form acute hospital to community healthcare. The IPACS simulation model is a high-level computer model of the discharge-to-assess (D2A) pathways. It takes a set of input parameters (from an Excel file) and estimates potential future service outputs (occupancy, number of patients with a discharge delay, number of days waiting for discharge, total system costs) based on different configurations of parameters. The model accounts for variation in inputs and outputs, and presents results over time. https://github.com/nhs-bnssg-analytics/ipacs-model