Medical Emergency Service (MES) or commonly known as ambulance plays a very important role in the possibility of mortality of a patient. MES has become an important issue in the world of health because of the possibility to survive a person. MES itself is preserved as an event occurrence ranging from for patient pick-up in a medical emergency to transfer of patient to hospital, but the main role of ambulance is to provide quick access to those in need or known as response time. This paper will conduct a literature review of the types of approaches that previous researchers have done to address MES-related issues. In the end can determine the direction of further research on MES.