Acquisition cost estimating methodology for aircraft conceptual design

摘要

The research was conducted in the light of a training programme which will train a totalof 150 engineers of AVIC I in Cranfield University during a period of 3 years.Cost has become an essential driver to aircraft design, as well as performances due toeither the limited defence budget or competitive airline market. Consequently, knowingthe possible cost prior to making actual expenditure will help managers to make properdecisions and allocate resources efficiently, and designers to optimize their work.Existing aircraft cost estimating models are outdated and mainly based on a databaseincluding both military and civil aircraft with various missions. This researchconcentrated on commercial jet aircraft and was to develop a suitable acquisition costestimating methodology for conceptual design from a commercial aircraftmanufacturer’s perspective.The literature reviewing took a comprehensive overview of some widely-applied costestimating methods: Analogy, Parametric, Bottom-up, Feature-based costing, Activitybasedcosting (ABC), Expert judgement, and etc. Some practical cost models were alsoreviewed to learn the application of cost estimating in the aerospace industry. Then,analogy and parametric approaches were selected to perform the methodologydevelopment considering the limited data available at the conceptual design phase.An investigation was deployed to identify the actual problems in practice. The resultshelped to recognize the needs of industry. Also, the preparation works for developmentare presented to understand the environment.With subjective judgement and statistical techniques, a series of cost estimatingrelationships (CERs) were achieved, in which some historic explanatory parametersremained or were eliminated, and some new ones introduced. Size of aircraft becameanother variable besides weight. As to engines, all developed explanatory variables havebeen revealed in prior researches. The validation of CERs proves that they can providereliable cost estimates with high accuracy and can be applied to conceptual design. Inaddition, a case study was conducted using a baseline aircraft defined in the groupdesign project (GDP) and presents cost forecasting for the proposed aircraft.At last, discussion and conclusion presents an overview of the research. A frameworkfor cost estimating system can be educed. Also, the future work is proposed for in-depthresearch.