aerospace Article A Web-Based Decision Support System for Aircraft Dispatch and Maintenance Hemmo Koornneef 1, * , Wim J. C. Verhagen 2 and Richard Curran 1   Citation: Koornneef, H.; Verhagen, W.; Curran, R. A Web-Based Decision Support System for Aircraft Dispatch and Maintenance. Aerospace 2021, 8, 154. https://doi.org/10.3390/ aerospace8060154 Academic Editor: Konstantinos Kontis Received: 2 May 2021 Accepted: 24 May 2021 Published: 28 May 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629HS Delft, The Netherlands; R.Curran@tudelft.nl 2 Department of Aerospace Engineering and Aviation, RMIT University School of Engineering, Building 57, Level 3, 115 Queensberry St., Carlton, VIC 3053, Australia; wim.verhagen@rmit.edu.au * Correspondence: H.Koornneef@tudelft.nl Abstract: Aircraft dispatch involves determining the optimal dispatch option when an aircraft experiences an unexpected failure. Currently, maintenance technicians at the apron have limited access to support information and finding the right information in extensive maintenance manuals is a time-consuming task, often leading to technically induced delays. This paper introduces a novel web-based prototype decision support system to aid technicians during aircraft dispatch decision- making and subsequent maintenance execution. A system architecture for real-time dispatch decision support is established and implemented. The developed system is evaluated through a case study in an operational environment by licensed maintenance technicians. The system fully automates information retrieval from multiple data sources, performs alternative identification and evaluation for a given fault message, and provides the technician with on-site access to relevant information, including the related maintenance tasks. The case study indicates a potential time saving of up to 98% per dispatch decision. Moreover, it enables digitalization of the—currently mostly paper- based—dispatch decision process, thereby reducing logistics and paper waste. The prototype is the first to provide operational decision support in the aircraft maintenance domain and addresses the lack of correlation between theory and practice often found in decision support systems research by providing a representative case study. The developed custom parser for SGML-based documents enables efficient identification and extraction of relevant information, vastly contributing to the overall reduction of the decision time. Keywords: decision support; aircraft maintenance; dispatch assessment; information retrieval; data integration; mobile tools 1. Introduction Maintenance is an essential element for ensuring the continuing airworthiness of aircraft and, by extension, the primary consideration in aviation: safety. Aircraft only add value to the airline when they perform revenue flights and airlines aim to minimize the so-called aircraft on ground (AOG) time. Traditional scheduled maintenance is based on calendar days, flight hours, or flight cycles, and decades of research on the optimization of maintenance scheduling to maximize aircraft availability has resulted in a solid body of literature (e.g., [1–4]). In recent years, a shift towards data-driven maintenance approaches can be observed, where, instead of a predefined interval, the current health or expected failure of the part or system is the determining factor [5–7]. These approaches aim to mini- mize the remaining useful life (RUL) of parts and systems before performing maintenance, to reduce maintenance costs and AOG time. The aforementioned maintenance strategies aim to prevent unexpected failures and their associated costs. Despite these efforts, unscheduled maintenance as a result of unex- pected failures remains a relevant factor in airline operations: it is estimated that 5.8% of all flights in Europe experience delays due to unexpected aircraft technical failures, resulting Aerospace 2021, 8, 154. https://doi.org/10.3390/aerospace8060154 https://www.mdpi.com/journal/aerospace