Abstract
Product innovations often involve changes to materials. Various material alternatives are typically sought to improve product quality. Currently, following the current trend of sustainable product development, it is necessary to consider environmental impact. This also applies to materials, particularly their acquisition method. At the same time, modern products should be characterized by low production costs. Despite this, there is a lack of a coherent, standardized method to support decisions about material selection by considering all these aspects during the design or product improvement phase. Therefore, the aim of this research is to develop a method for selecting materials during final product improvement, taking into account quality, environmental impact in the life cycle context, and manufacturing costs. The method is implemented in eight stages and involves calculating the following indicators: (i) quality (satisfaction with use), (ii) environmental impact (for material extraction and acquisition), and (iii) decision-making based on manufacturing costs. Calculations to obtain these indicators were performed using OpenLCA 2.0.0 with the Ecoinvent database, formalized scoring (PS), cost analysis, and morphological analysis. The results of the method lead to the selection of favorable hypothetical prototypes resulting from the proposed material changes. The method was tested using a six-speed manual transmission from a light vehicle. The results showed that the decision-making process for selecting a prototype from among possible material modifications varies. The proposed method can be used for any newly created or modified product at the material selection stage.