Impact of Arrivals on Departure Taxi Operations at Airports

Aircraft taxi operations are a major source of fuel burn and emissions on the ground. Given rising fuel prices and growing concerns about the contributions of aviation to air pollution and greenhouse gas emissions, recent research aims to develop strategies to reduce fuel burn at airports. In order to develop such strategies, an understanding of taxi operations and the factors that affect taxi-out times is required. This paper describes an analysis of taxi-out times at two major U.S. airports in order to identify the primary causal factors affecting the duration of taxi-out operations. Through an analysis of departures out of John F. Kennedy International Airport and Boston Logan International Airport, several variables affecting taxi-out times were identified, including primarily the number of arrivals and number of departures during the taxi-out operation of an aircraft. Previous literature suggests that the number of arrivals on the surface has limited influence on taxi-out times; however, this analysis demonstrates that the number of arrivals is in fact significantly correlated with taxi-out times. Furthermore, we find that arrivals have a greater impact on taxi-out times under runway configurations where there is increased interaction between arrivals and departures

A Redesign Framework for Call Centers

An important shortcoming in the Business Process Redesign (BPR) literature is the lack of concrete guidance on how to improve an existing business process. Our earlier work has aimed at filling this gap by identifying a set of BPR best practices. This paper takes a further step by showing how a set of best practices can be used to derive a redesign framework for a specific domain, in this case for call centers. Such a framework identifies the various available design options and specifies the relevant performance characteristics. To evaluate concrete design configurations (i.e., coherent combinations of design choices) we use a formal modelling approach based on Petri nets and the simulation tool CPN-Tools. An industrial case study is used to gather relevant context data. We expect that this work helps researchers and practitioners to optimize the performance of actual call centers and to set up similar frameworks for other domains