Abstract
Within the aerospace, defence, space, and security (ADS) industries, there is a growing reporting requirement and interest in understanding and reducing the environmental impacts of products and related risks to business. This dissertation presents the research carried out in collaboration with six ADS companies (ADS Group, Airbus Group, BAE Systems, Bombardier Aerospace, Granta Design, and Rolls-Royce) to establish industry methods for consistently measuring and reporting two pre-selected product-based environmental indicators identified as important to the industry: energy consumption and access to resources. Following an action research approach, four potential methods for calculating and reporting the manufacturing energy footprint of ADS products were identified and industry tested on three case study parts selected by Airbus Group, Bombardier Aerospace, and Rolls-Royce. Methods tested were: (1) Direct measurement, (2) Theoretical calculation, (3) Facility level allocation of energy consumption (based on annual production hours, quantity, and weight of parts manufactured), and (4) Approximation based on generic data. Method 3 (Production Hours) was found to be the most suitable “single” method for immediately reporting the manufacturing energy footprint of parts as it was quick to implement and based on widely available industry data. Regarding the comparability of methods, methods were found to be incomparable and produce significantly different results when applied to calculate the manufacturing energy footprint of the same part. Differences in the comparison of two methods could be in the order of one magnitude based on findings. Such large differences are significant for understanding energy use/costs, environmental impacts (e.g. carbon footprint), and reliably reporting and comparing information for informing decisions. Therefore, methods for calculating the manufacturing energy footprint of products cannot be assumed to be interchangeable and stacked in LCAs, EPDs, and other standards. These findings challenge current LCA practices and the interpretation of product-based environmental declarations if multiple methods have been used and results stacked. Thus, existing standards and growing product-orientated environmental polices allowing for the use of multiple methods (e.g. EPDs and PEFs) may indeed proliferate incomparability rather than engender comparability. Regarding approximating product energy footprints using generic data, the research was only able to approximate the machining energy consumption associated with the case study parts because of data gaps in the generic database. However, a high comparability between generic data use and direct measurement (i.e. specific/primary data) was found. These limited findings challenge attitudes towards generic data use and indicate potential scope to replace expensive primary data collection with more cost-effective (and similarly accurate) generic data. With regards to proposing a method for measuring the access to resources (A2R) product-based environmental indicator, several supply risk indicators and methodological choices for measuring the indicator were identified. Methodological choices included decisions such as to normalise and aggregate supply risk indicators into a single score. A workshop with the industry consortium was consequently carried out to explore and agree: (1) what indicators should be selected to appropriately measure A2R, and (2) how the selected indicators should be measured. Out of 18 potential supply risk indicators, five were identified as key: conflict material risk, environmental country risk, price volatility risk, sourcing and geopolitical risk, and monopoly of supply risk were selected because of clear links to legislation, use of reliable data, and effect on material prices. Regarding methodological choices for measuring A2R, the industry consortium preferred to avoid normalising and aggregating indicators to prevent masking information. The dissertation highlights several major contributions to knowledge, industry, policy, and the development of standards as a result of the research. The main contribution to knowledge is the methods developed and the learnings derived from the process undertaken to determine them. The main contribution and benefit to the ADS industries are single, practical, research informed, and industry consortium agreed methods for cost-effectively measuring two product-based environmental indicators (which support the informational requirements of a wide range of stakeholders and potential end-uses). The examined indicators and the 'case study’ approach utilised with an industry consortium to identify the generic issues in developing suitable methods will be of value for: (1) other industries with similar product/value chain characteristics, and (2) the development of methods for measuring other product-based environmental indicators for industry use (e.g. water, waste, recyclability, etc.). Presented research outcomes provide valuable industry insights for informing the development of emerging product-orientated environmental policies and standards in a manner which benefit the ADS industries and broader environment. Overall, the research has enhanced academic understanding and provides industry capability to support businesses and other similar industries to consistently assess, report, and improve the sustainability of their products and supply chains.