EOSC-SIESTA is developing a platform for the analysis of sensitive data within the European Open Science Cloud, demonstrating the feasibility of adopting FAIR principles throughout the different phases of the data lifecycle. This needs a complete analysis of the data needs and expected results, so that decisions can be made during this initial stage on how to handle the data throughout the project. Our approach aims to ensure the adoption of FAIR principles while facilitating the availability and reusability of the research outputs. The current document is the initial version of the Data Management Plan (DMP), describing the approach adopted to facilitate data management throughout the entire project lifecycle. The DMP will systematically document and monitor the diverse research artifacts that are needed or will be produced throughout the project, taking into account the particularities of the EOSC-SIESTA project.