Analyzing and improving air cargo terminal operations

Abstract

In this thesis we study two research problems regarding cargo terminals. Firstly, the performance of cargo retrieval operations is analyzed for the objective of improving it. Due to the complex nature of cargo handling operations and stochastic customer requests and processing times, which make formulation of analytical model difficult, a Petri Net model is developed to describe the retrieval process, from which a corresponding discrete event simulation model is developed. Secondly, we propose a new storage policy for Automated Storage/Retrieval Systems in import terminals, which reduces the expected Storage/Retrieval machine travel time. A discrete time Markov chain model is proposed, which computes the exact travel time. An approximation model is developed which gives static estimation on the travel time with less computational effort. Finally, a simulation model is employed which can solve real industrial-size problems. The reservation storage policy provides the minimum expected travel time compared with other storage policies.