This thesis focuses on developing a centralized dishwashing service with the goal of reducing the amount of disposable tableware waste generated at Avinor Oslo Airport. Moreover, the project aims to help Avinor Oslo Airport achieve its objective of becoming a zero-waste airport by 2030. The research process followed the Triple-diamond model, facilitating a structured approach through mainly three phases: Understand, Ideate, and Develop. The ‘Understand’ involves the study of the literature review, analysis of existing practices, field research, and stakeholder interviews to gain an understanding of the context. During the ‘Ideate’ phase three concepts were developed and evaluated through iterative testing and feedback. Finally, at the ‘Develop’ phase, the final concept, Green Circles, is developed. Green Circles is a centralised dishwashing service for reusable takeaway containers, that allows passengers to drop the containers at drop-off machines at the boarding gates and airport exists. The implementation of Green Circles is expected to significantly reduce single-use tableware waste at Avinor Oslo Airport. The study highlights the importance of stakeholder engagement, convenient passenger experience, and efficient operational integration. Broader implications suggest that similar services could be adopted in other airports, contributing to the aviation industry’s sustainability efforts, such as those proposed by TULIPS.