The treatment concept of infected pancreatic necrosis (IPN) has experienced a historic shift from open necrosectomy (ON) to minimally invasive approach. However, the role and status of ON in IPN are still accepted both in domestic and foreign guidelines. Determining the indications and timing of ON to maximize the clinical benefits in IPN has been a vital problem faced by the multidisciplinary team of severe acute pancreatitis. Here, the authors elaborate the indications and timing of ON under new treatment concept based on recent advances, and discuss the practice of process reengineering for the step-up approach.