The University of Milan has been committed for years in supporting open science and in underlying criteria of transparency, accessibility and reproducibility. For years, the openness of publications and data has been supported with ad hoc fundings, extensive training courses especially dedicated to early career researchers, a diamond university press, and the communication of the results achieved at the national and international level. Open science is one of the goals of the university's strategic plan, which aims to implement at least 6 of the European Commission's 8 pillars. Consequently, openness, transparency and reproducibility are also among the goals of departments, research groups and individuals researchers, whose research results are reported publicly in reports and dashboards. The university has also recently joined the Barcelona declaration on open research information, reaffirming its existing commitment from 2023 to the exclusive use of open data for research analysis and monitoring. Over the past 10 years, therefore, the university has worked to make a cultural change effective, working on training but also on open and transparent documentation of achievements. In this, collaboration with European alliances has been crucial. All that considered, the time is ripe to initiate a series of short- and medium-term actions, described in this action plan, that take into consideration the state of the art in the institution and the results already achieved, the challenges posed by the national context and the constraints imposed by the Ministry of Research, which therefore represents an interlocutor whom to deal with together with all the other signatory institutions and the members of the National Chapter.