Aircraft Cost Modelling using the Genetic Causal Technique within a Systems Engineering Approach

The paper is primarily concerned with the modelling of aircraft manufacturing cost. The aim is to establish an integrated life cycle balanced design process through a systems engineering approach to interdisciplinary analysis and control. The cost modelling is achieved using the genetic causal approach that enforces product family categorisation and the subsequent generation of causal relationships between deterministic cost components and their design source. This utilises causal parametric cost drivers and the definition of the physical architecture from the Work Breakdown Structure (WBS) to identify product families. The paper presents applications to the overall aircraft design with a particular focus on the fuselage as a subsystem of the aircraft, including fuselage panels and localised detail, as well as engine nacelles. The higher level application to aircraft requirements and functional analysis is investigated and verified relative to life cycle design issues for the relationship between acquisition cost and Direct Operational Cost (DOC), for a range of both metal and composite subsystems. Maintenance is considered in some detail as an important contributor to DOC and life cycle cost. The lower level application to aircraft physical architecture is investigated and verified for the WBS of an engine nacelle, including a sequential build stage investigation of the materials, fabrication and assembly costs. The studies are then extended by investigating the acquisition cost of aircraft fuselages, including the recurring unit cost and the non-recurring design cost of the airframe sub-system. The systems costing methodology is facilitated by the genetic causal cost modeling technique as the latter is highly generic, interdisciplinary, flexible, multilevel and recursive in nature, and can be applied at the various analysis levels required of systems engineering. Therefore, the main contribution of paper is a methodology for applying systems engineering costing, supported by the genetic causal cost modeling approach, whether at a requirements, functional or physical level.

Whole-Life Costing for Capability

In recent years, there has been growing emphasis on the need to provide transparency in the costs of engineering programmes, leading to growing emphasis on Whole Life Cost (WLC) modelling techniques. This has arisen largely due to the increased interested in longer timescale projects and programmes, combined with the emergence of system-of-systems and network enabled capability concepts. This change in the implementation and management of large scale projects has necessitated the development of alternative methods of evaluating performance. This work seeks to address the shortfalls in current costing methodologies when applied to these highly flexible environments, and to propose a conceptual model for dealing with the encountered complexities. The approach has a fundamental role and potential significance in the future of whole life costing for Network Enabled Capability (NEC) but can also offer a potential paradigm shift for costing in traditional engineering environments.