Ambulance routing problem for relief operations with patient groups and semi soft time windows

Quick response to the urgent relief needs in metropolis is vital to alleviate the disaster impacts in the affected areas. In disaster situations, many people call emergency services simultaneously, but the number of emergency vehicles are not sufficient to visit all the victims immediately. This paper studies ambulance fleet management to minimize the total service completion time among all patients in disaster response phase. Since, the victim’s condition get worse and become life threatening over the time, semi soft time window constraint is incorporated to reflect penalties on late arrivals. In order to utilize the ambulances efficiently, we subdivide the patients to three groups based on their severity of injuries and allocate the ambulances to the patients according to vehicle capabilities. In the following, the problem is implemented by the GAMS software and various numerical instances are generated to evaluate the proposed model. Finally, a sensitivity analysis is presented to assess the relationship between the problem structures and optimal solutions.

Keywords:

Ambulance routing problem , Ambulance classification , semi soft time windows , Disaster response , Completion time