The increasing amount of process execution data, i.e. the event logs stored by the company, can be exploited using Business Process Simulation (BPS). BPS serves as a valuable tool for business analysts, enabling them to analyze and compare business processes and identify changes that optimize key performance measures. Especially when evaluating alternative scenarios, it is crucial to start with an accurate simulation of the current process. Recent research in the field of BPS has demonstrated that Hybrid Simulation Model (HSM) approaches reliably replicates business process behaviour, overcoming the unrealistic or oversimplified assumptions often found in traditional discrete event simulators. In this paper, we present a case study conducted in collaboration with EY, where we apply the HSM to a real-life business process log. This study demonstrates the benefits of the HSM for business process analysis and its potential to improve process performance.