Disassembly knowledge classification and potential application: A preliminary analysis on a washing machine

Circular economy is largely recognized as the univocal economic model that guarantees a long-term sustainability, decoupling the economic growth and the finite resources consumption. As a prerequisite, it requires to realize product closed-loop lifecycles. However, the management of the EoL phase during the design process is a complex task, due to the fact that it is the most far away phase, in terms of time, from the moment of the product conception. For this reason, usually, manufacturers and EoL stakeholders do not actively collaborate in optimizing the product lifecycle performances. This paper wants to overcome this lack proposing a method to formalize, collect and classify the EoL knowledge. The main outcome is a structured database containing positive and negative knowledge about best practices and disassembly problems faced during dismantling activities. The knowledge classification rules are based both on product characteristics (e.g. product families, target components, assembly methods, etc.) and on other more general aspects (e.g. motivations of the disassembly, handling difficulties, etc.). Through the sharing of this knowledge, the gap between design departments and EoL stakeholders can be reduced with the aim to improve EoL performances and the overall resource efficiency. This work is focused on an out-of-service washing machine case study. The product has been manually disassembled by expert operators, observing and rating the significant problems. Their interpretation has allowed to create a set of specific design guidelines, organized according to the defined rules. The classified knowledge has been used by non-expert designers (undergraduate students) as a tool to guide the redesign activities. Different design solutions (e.g. homogenization of screws, reduction of component number, etc.) have been implemented to configure a new washing machine version, improved from the disassemblability point of view. The obtained results have confirmed the usefulness of the disassembly knowledge sharing in supporting Design for EoL activities and, furthermore, in non-skilled operators training. In conclusion, this research work contributes to the state of the art linking stakeholders involved in the Beginning of Life (BoL) with stakeholders responsible of the EoL management. Furthermore, the proposed work leads to relevant improvements in product lifecycle performances. The proposed knowledge database represents the needed resource to effectively extend the producer responsibility and to close the current gap between manufacturers and dismantlers.