THE RESEARCH ON AIRCRAFT RDTE COST BASED ON GRAY CORRELATION ANALYSIS THEORY AND EQUALATION-ENGINEERING-VALUE-RATE

摘要

Recently, technology advance in aerospace industry and the introduction of factors as life cycle cost (LCC) make a change of design ideas and design emphases for aircraft. Aircraft design is making a shift from traditional "optimum design for performance " to "design for affordability and quality". Aircraft design is shifting and extending the tradeoffs between traditional disciplines as aerodynamics, propulsion, structure etc to the tradeoffs between these traditional disciplines and non-conventional disciplines including subjects like reliability, maintainability, safety and survivability, as well as crossover disciplines as economics and stability. Economics is becoming a key factor that decision makers judge optimal scheme from some feasible design concepts of aircraft. As the economics metrics, life cycle cost of aircraft is an important design index for modern aircraft system and is one of the key metrics of evaluating the goodness of design scheme for aerospace product. Furthermore, the analysis of life cycle cost is the basis of cost-effectiveness analysis on aircraft. The research, development, test, and evaluation (RDT&E) cost are an important part that makes up the total life cycle cost (LCC) of an aircraft. A method based on gray correlation analysis theory and equalation-engineering-value-rate method for estimating RDT&E cost of aircraft especially in early conceptual design stage is presented. The first task of establishing cost model in the parametric method of life cycle cost is to determine the cost drive factor. Based on large amount of historical data at home and abroad, using the method of gray correlation analysis in gray system theory, the article establishes the determination method of cost drive factor, which overcomes the shortcoming of the lack of data. Combining the features of less known knowledge in early conceptual design stage for aircraft design, the authors propose the definition of equalation-engineering-value-rate and study the RDT&E cost for aircraft by applying the method of equalation-Engineering-value-rate to modify the existed cost model on the basis of the determined cost drive factor and historical data. The method proposed provides a new theory for the establishment of LCC model for aircraft top-level design. Furthermore, the method provides the decision gist for the decision tradeoffs of early stage in aircraft design, and establishes the basis for cost/effectiveness analysis in aircraft design.