A computer apparatus to identify healthcare resources used by a medical institution, comprising: a memory storing instructions for execution by a processor, the processor configured by the instructions to provide: a knowledge graph builder; and a knowledge graph customizer; wherein: the knowledge graph builder is arranged to input open data and clinician information, to generate a set of medical services terms and a set of medical resources terms from the open data and clinician information, and to associate the medical resources with the medical services to build a knowledge graph; and the knowledge graph customizer is arranged to match the knowledge graph with records of the medical institution to provide a customized subgraph of the knowledge graph which is specific to the medical institution.