A framework for the architecting of aerospace systems portfolios with commonality

Abstract

(cont.) The framework was applied to three case studies: commonality analysis for a portfolio of future and legacy exploration life support systems, for the historical Saturn launch vehicle portfolio, and for a portfolio of future lunar and Mars surface pressurized mobility systems. The case studies demonstrate the broad applicability of the methodology and provide insights into the impact of commonality on key portfolio metrics. Results indicate that commonality can enable life-cycle cost savings of 10% or more, dependent on the type of systems in the portfolio. The results further indicate that commonality can enable significant reductions in the number of custom development projects that need to be carried out in the portfolio; reductions of 50% or more were observed, dependent on the type of systems in the portfolio. As each project carries developmental risk and cost overhead, the reduction of the number of projects and the associated simplification of the portfolio must be considered a strong driver for commonality in aerospace systems portfolios.

Aerospace systems are increasingly being developed as part of portfolios, or sets of related aerospace systems whose design and production is controlled by a single organizational entity. Portfolios enable synergies across the constituent systems that can reduce portfolio life cycle cost and risk; one important synergy is commonality between the systems in the portfolio. Commonality in the form of technology and design reuse between and within systems can lead to significant benefits in life-cycle portfolio cost and risk; however, commonality usually incurs up-front and life-cycle cost and risk penalties due to increased design complexity. A careful trade-off of these benefits and penalties is required in order to assess the net benefit of specific commonality opportunities in the portfolio. This trade-off needs to be carried out during the architecting stage of the portfolio life-cycle when the leverage to improve life-cycle cost and risk is greatest. Existing analysis methodologies are generally focused on commonality as indicated by similarities in design parameters and therefore have limited applicability during the architecting stage. This thesis provides a framework for the identification and assessment of commonality opportunities in aerospace systems portfolios during the architecting stage. The framework consists of a set of principles which are intended to provide general guidance for the portfolio architect, a methodology that transforms a solution-neutral description of an aerospace systems portfolio into a set of preferred portfolio design solutions with commonality, and a heuristic commonality screening tool which is integrated into the methodology.