The last airmile

Abstract

The frequency of occurrence and the size of natural disaster is increasing, with more people to beaffected in the coming years. The impact is huge, with major infrastructures being damaged andaccess to basic needs cut off for the disaster struck regions. The affected regions and communitiesare dependent on the delivery of disaster relief aid, by governments and non-governmental orga-nizations. The delivery can be difficult, while airports, harbours and other infrastructure is oftendamaged from the disaster.The timely delivery of relief aid to the affected communities is a major challenge of today. Theairports used for the distribution of relief items are often unable to handle the shear size of theinflux of these items. The resources are damaged and personnel might not be able to show up forwork. In order to reduce the overexertion of the local airport, an airbridge can be made with aregional airport. The regional airport can then be used as a buffer, for bundling and storing reliefaid, until it can be delivered to the local airport. The system in which the regional airport receivesthe international contribution of relief items and sends them in a moderated flow to the local airportis called the airport relief chain.The relief chain is subject to several bottlenecks, but due to scarcity in research, the influenceon airport relief chains had not been identified previously. Reducing these bottlenecks and im-proving the relief chain can be achieved by improving the processes on individual airports, as wellas by altering small features in the structure of the relief chain itself. The research question isconsequently:How can the impact of bottlenecks on an airport relief chain system be decreased,considering the airport operations in a fixed network design?To be able to confirm the bottlenecks and investigate possible solutions, a simulation model wasbuilt for the airport relief chain system. To obtain relevant outcomes, data of a real world casestudy was applied to the simulation model. The case study of choice is the earthquake followed bya tsunami in September 2018, that struck the island of Palu, Indonesia. In this disaster, an airportrelief chain system was created, in which the delivery to Mutiara on Palu, serving as the local air-port, was provided through Sepinggan airport on Kalimantan, serving as the regional buffer airport.To this end three bottlenecks were identified for the airport relief chain. namely: (1) The air-craft arrival process at the regional airport, (2) The cargo handling after unloading of the aircraftat the regional airport, and (3) the airbridge connection between the local and regional airport. Thebottleneck at the airbridge is the most stressing, absorbing most of the cargo. Even when the otherbottlenecks are resolved, without improvement in the airbridge the performance will eventually belimited.With the airbridge as a major constraint in the airport relief chain system, the delivery of re-lief items can not be larger than the throughput of the airbridge. The bottlenecks identified at theaircraft arrival and the regional airport processes reduce the flow of relief items even further. Thepolicies investigated are meant to maximize the performance up to the airbridge, creating maximalperformance within the constraints of the system.The performance was measured through the performance indicator, namely the timely delivery.ii
The timely delivery consists oftotal deliveyand theshare of priority demand delivered. The perfor-mance of the system as a whole can as such be evaluated, yet it lacks detail for the implementation ofpolicies. In order to improve the system, the bottlenecks had to be identified, for which the bottle-neck identification measures were introduced. These consist ofidle cargoandthroughput time. Theidle cargo is generally a notification for the occurrence of a bottleneck, with high average idle cargomeaning a bottleneck occurs. The throughput time here indicates whether it was very impacting,as high numbers for throughput time generally mean less impact on the overall component over time.The individual policies were ineffective to truly improve the airport relief chain as a whole. Severalpolicies proved to be quite effective at reducing bottlenecks, thus improving the timely delivery.However, only small improvements were seen in the total delivery, due to the downstream occur-rence of other bottlenecks. Theshare of priority demandalone could be raised effectively throughprioritization policy. Those policies would not provide further system improvements, making theiruse even more case specific.In order to improve on the timely delivery indicators, which includes the total delivery, combina-tions of inventory management policies and airport policies were examined. Based on the individualperformancesdestination prioritizationthrough use of off-airport storage anditem prioritizationon the most stressing relief type were chosen as the inventory management policies. These, if pairedwithadditional workerspolicies, were able to absolve the bottlenecks in the system up to the air-bridge. The combinations as such performed at the optimal range, considering the final constrainton the system and are preferable for implementation.The prioritization policies were the most useful, but require staff and their equipment to fullyperform. As such the processes in an airbridge system for the provision of relief items should con-sider the capacity at the regional airport and optimize the processes accordingly up to the airbridgeitself.