Value–driven decision-making process for application to an aeronautical case study

Abstract

The latching mechanism of a Lower Deck Cargo Door (LDCD) of an aircraft is considered one of the most crucial and important systems that compose the overall structure of a cargo door. The main function of such a mechanism is to keep the LDCD in a closed and locked position throughout the flight and in an open and locked position when required.The identification of a latching mechanism, among others, as the optimum alternative requires the implementation of a well-structured decision-making process, balancing multiple attributes. Particularly, in the current thesis, a comparative analysis is carried out among three already developed latching mechanisms: Hook Spool Latching Mechanism (HSLM), Bar Latch Mechanism (BLM) and C-Latch Mechanism (CLM). Each architectural design is evaluated by seven different Key Performance Indicators (KPIs) which are derived from four specific domains: Sustainability Domain, Reliability Domain, Performance Domain and Supply Chain Domain. By applying the Multi Attribute Utility Theory (MAUT), trade-off analyses and decision-making are performed.By implementing the outlined methodology for the estimation of the considered KPIs, it is observedthat the first architectural design (HSLM) is the most reliable and sustainable. The CLM stands out for the lowest mass whereas, the BLM demonstrates the best supply chain performance.Furthermore, according to the reference case study (equal weights and linear utility functions have been assigned to all KPIs), some of the resulting alternatives are being identified as the optimum solutions (6 in total), as they combine relatively high value and low overall cost. Nevertheless, when some of the indicators are prioritised, those optimum solutions may be changed as is demonstrated in other examined case studies. This underlines the importance of contextual decision-making, where trade-offs must be carefully evaluated based on the demands and constraints of the particular research.Generally, the identification and evaluation of judicious trade-offs among various attributes assist in improving the overall reliability and effectiveness of the latching system. The present framework has been developed for a latching system of a cargo door, however with some modifications, it can easily be adopted by other aeronautical or non-aeronautical systems.