Background Resilience engineering has been advocated as an alternative to the management of safety over the last decade in many domains. However, to facilitate metrics for measuring and helping analyze the resilience potential for emergency departments (EDs) remains a significant challenge. The study aims to redesign the Hollnagel’s resilience assessment grid (RAG) into a custom-made RAG (ED-RAG) to support resilience management in EDs. Methods The study approach had three parts: 1) translation of Hollnagel’s RAG into Chinese version, followed by generation of a tailored set of ED-RAG questions adapted to EDs; 2) testing and revising the tailored sets until to achieve satisfactory validity for application; 3) design of a new rating scale and scoring method. The test criteria of the ED-RAG questionnaire adopted the modified three-level scoring criteria proposed by Bloom and Fischer. The study setting of the field test is a private regional hospital. Results The fifth version of ED-RAG was acceptable after a field test. It has three sets of open structured questions for the potentials to respond, monitor, and anticipate, and a set of structured questions for the potential to learn. It contained 38 questions corresponding to 32 foci. A new 4-level rating scale along with a novel scaling method can improve the scores conversion validity and communication between team members and across investigations. This final version is set to complete an interview for around 2 hours. Conclusions The ED-RAG represents a snapshot of EDs’resilience under specific conditions. It might be performed multiple times by a single hospital to monitor the directions and contents of improvement that can supplement conventional safety management toward resilience. Some considerations are required to be successful when hospitals use it. Future studies to overcome the potential methodological weaknesses of the ED-RAG are needed.