Challenges in assessment implementation include assessment blueprinting, accuracy and timeliness of result processing, item analysis and personalised feedback. These challenges were addressed by an online assessment system (OAS) that translates the educational framework of outcome-based education (OBE) into an integrated platform applicable across academic programmes. OBE principles of transparency, measurability, relevance, and individualisation was feasibly addressed using technology. The system development required continuous stakeholder engagement and feedback. Its implementation involved change management at institutional level with shifts in procedures, responsibilities, staff competencies and resource allocation. This article describes approaches taken and the lessons learned in developing and implementing OAS to enhance assessment practice for medical science programmes.