The paper describes MEDIS (Medical Device Information System), a system developed to support the whole lifecycle of a Clinical Investigation (CI) for Medical Devices, providing details on the approach used in its development. MEDIS is a software system that collects and manages data and documents, exchanged between an applicant and the Italian National Competent Authority during all the phases of the business process, from the CI notification up to the submission of the final results. The development of the MEDIS Domain Analysis Model (DAM) following the HL7 v.3 methodology as well as the approach followed in the system implementation are discussed in relation to the business domain peculiarities.