ASSESSMENT-BASED ECO-EFFICIENCY ESTIMATION OF COMPOSITE AND HYBRID STRUCTURES IN COMMERCIAL AIRCRAFT

In the early development stage, decision-makers select the product specifications. These demand-oriented specifications are achieved by configuring the associated processes. Such decision-making may be involved with various life-cycle stages and multiple development disciplines. Therefore, decision-support systems (DSSs) are essential to facilitate the decision-making process on strategic, tactical, and operational managerial levels. To consult the decision-makers, success factors are to be defined and evaluated. Success factors such as the sustainability aspects such as economic and ecological impacts may be evaluated on different levels starting from the global key-result indicators (KRIs). To serve different managerial levels by such DSSs, combining what are known as top-down and bottom-up evaluation approaches is crucial. In practice, a DSS provides the assistance regarding a specific selection of KRIs. In this work, economic as well as ecological KRIs are evaluated by the applied DSSs. Therefore, two DSSs are discussed in this paper. The first DSS is the Eco-Efficiency Assessment Model (EEAM), which has been developed by the German Aerospace Center (DLR) as a bottom-up assessment tool for the production of composite and hybrid structures. In this work, EEAM is implemented to assess the economic and ecological KRIs of the “as-is” prototype manufacturing process at DLR laboratories. Based on EEAM, an Eco-Efficiency Estimation Model (E³M) is developed as the second DSS in this work. E³M evaluates the economic and ecological impacts of the “as-if” industrial scenarios by deriving a top-down estimation based on the bottom-up assessment. The advantage of this approach is the possibility of validating the data-based bottom-up assessment and consequently the assessment-based estimation. As a case study, a novel design of a suction rib for a hybrid laminar flow control (HLFC) wing is selected in this work. While HLFC offers advanced performance during operation phase in the life-cycle of commercial aircraft, decision-makers need to investigate the performance of the selected KRIs such as direct cost and carbon footprint in the other life-cycle phases. Despite the fact that all other phases are decisive, this work focusses on the manufacturing process. After performing a data-based eco-efficiency assessment of the “as-is” suction rib manufacturing, an estimation of “as-is” industrial manufacturing is derived. The results of both “as-is” and “as-if” scenarios show a reduction in the direct manufacturing cost of the suction rib from 4.9 k€/kg of the final structure to 0.395 k€/kg, in the carbon footprint from 313.9 kg CO2/kg to 93.7 kg CO2/kg, as well as the by the product material waste from around 65% to 38% respectively