Take-aways from a project between Oslo University Hospital and software vendor DIPS in replacing old system for Artificial Reproductive Technology (previously known as IVF) with modern software based on openEHR, using principles in openEHR known as dual modelling. Clinically led modelling of clinical information models (openEHR archetypes) and templates contributing to more precise software development. Benefits and downsides, lessons learned both from a project management and technical point of view.