Emergency departments’ capacities to deal with a patient surge (the number of patients increases in a short period of time) play an important role in preparedness for natural or man-made disasters. This paper examines how emergency departments could improve their capacities by optimizing the workflow. A framework is proposed to reconfigure the workflow to improve capacity while maintaining treatment equality. Our results show that reducing lower priority processes and combining originally separate processes can shorten patient total waiting time in the emergency department.