Purpose: Two life cycle assessment (LCA) studies comparing a new low-particulate-matter-emission disc brake and a reference disc brake were presented. The purpose was to identify the difference in potential environmental impacts due to a material change in the new disc brake parts. Additionally, the validity was investigated for the simplification method of omitting identical parts in comparative LCA. This was done by comparing the results between the simplified and the full LCA model.

Methods: The two disc brakes, new disc brake and reference disc brake, were assessed according to the LCA ISO standards. The ReCiPe 2016 Midpoint (hierarchist) impact assessment method was chosen. Simplifying a comparative LCA is possible, all identical parts can be omitted, and only the ones that differ need to be assessed. In this paper, this simplification was called comparative LCA with an omission of identical parts.

Results and discussion: The comparative impacts were analysed over seventeen impact categories. The new disc brake alternative used more resources during the manufacture of one disc compared to the reference disc brake alternative. The shorter life length of the reference disc demanded a higher number of spare part discs to fulfil the same functional unit, but this impact was reduced due to material recycling. The new disc brake impacts were connected primarily to the coating and secondly to the pad manufacture and materials. The validity of the simplification method was investigated by comparing the results of the two LCA models. The impact differences were identical independent of the LCA model, and the same significant impact categories could be identified. Hence, the purpose of the study could be fulfilled, and the simplification was valid.

Conclusions: Both LCA models, simplified and full, revealed that the new disc brake had limited environmental advantages. The omission of identical parts made it more challenging to determine if an impact was significant or insignificant. The simplification seemed to be reasonable.

Transport of goods and people is increasing and causing strains on the environment. Road vehicles emit exhaust and non-exhaust emissions. One significant contributor to non-exhaust emissions is particulates generated through wear from braking. The particulates originate from the contact surfaces of the pad and the disc. Particulate emission is a known issue with considerable impacts on plant, animal, and human health. In the EU Horizon 2020 LOWBRASYS (a LOW environmental impact BRAke SYStem) project (LOWBRASYS, 2017), one of the objectives was to design a novel disc brake that reduces particulate generation during braking. One of the results is a novel disc brake with disc and pad-materials that indicate a significant decrease in particulate formation during use. This is accomplished by changing the materials of the contact pair regarding composition and coatings (Wahlström, Lyu, Matjeka, & Söderberg, 2017). Materials used in the disc brakes cause environmental impacts during their life cycle. Some parts and processes need for example critical raw materials such as tungsten, cobalt, and more (European Commission, 2017). This paper evaluates a material selection tool with an environmental perspective for product developers called Eco Audit (Ashby et al. 2008). This tool is featured in the CES Edu Pack software provided by Granta Design, Cambridge University (Granta 2018). The purpose of this study is to evaluate if the Eco Audit tool can provide a fast and valid impact assessment from an LCA perspective. Results of the Eco Audit compared to the SimaPro results indicate that it is possible to make valid conclusions. The validity of the tool is connected to the purpose of the study. If the purpose is to identify critical life cycle phases and environmental impacts, then the tool can accurately aid the user. It could potentially be difficult to make valid conclusions when assessing a product with more complex processes or advanced materials. The tool's strengths are the simplicity and easy accessibility for any user. The trade-off is precision, robustness, and representativeness of the target. 

Alongside the economic growth demands for further use of resources increase as well. As a result of this transportation of industrial products all over the world will also increase, in particular through shipping. In this study a new innovative concept for transport of cargo, the CargoXpress vessel, is presented and analysed over the life cycle in terms of costs and environmental effects. In the life cycle cost analysis the influence of future price scenarios for LNG-fuel and structural material is investigated through sensitivity analysis. For the environmental study life cycle assessment is used according to ISO 14044:2006. In direct comparative analysis the environmental impacts and costs over the life cycle of the new vessel is compared to road transport by truck. Then also analysis is made by selecting different existing transport scenarios were the new vessel is compared to road transports. The results from both cost and environmental analysis clearly present benefits for transporting goods with the CargoXpress vessel. Regarding the cost several factors in combination plays an important role for the outcome as initial investment cost, price development of fuel and interest rate. For the environmental analysis the innovative vessel is shown to be the preferable alternative.