The mission of the ELIXIR Data Platform is to deliver a sustainably funded portfolio of Core Data Resources that exemplify excellence within a coordinated and vibrant ecosystem of Node Data Resources, to meet the needs of the European life science research community. The overall objective of Work Package 3 is to build a framework to inform and drive the sustainable development of Europe’s Core life-science Data Resources. ELIXIR aims to ensure that these resources are available long-term and that the life cycles of these resources are managed such that they support the scientific needs of the life sciences and biological research. In addition, Work Package 3 promotes excellence in resource development and operation through providing a unified framework for the identification and monitoring of key bioinformatics resources across Europe. Running two iterations of the process to select ELIXIR Core Data Resources has informed us how best to collect all the required indicators. While some indicators never or rarely need updating, others can only be collected manually. As discussed in detail in this report, some indicators are automatically collected on a local level, while for others, collection can be centralised. The adopted approach therefore maintains a pragmatic balance between automated collection (local and centralised) and manually collated updates. The Core Data Resource selection and update processes that are currently in place only require modest human resources at the ELIXIR Hub and little specialized technical knowledge, making these processes easily sustainable over time. Having defined the Core Data Resources, and implemented annual collection of Indicator data, Work Package 3 has produced an article “The ELIXIR Core Data Resources: fundamental infrastructure for the life sciences” and posted it as a preprint on bioRxiv as well as submitting it to the Bioinformatics journal. This is the first such analysis to be conducted on such a collection, and will be a powerful tool in the ongoing work towards long term sustainability of life science data resources.