Determining what makes an Information System (IS) successful is an ongoing concern for both researchers and practitioners alike. Arriving at an answer to this problem is compounded by the subjective nature of success and therefore trying to make judgements of what is and is not a success is problematic. Despite these difficulties system use has become more accepted as a measure of system success. Following this logic if a system is accepted it will have a higher likelihood of being used and therefore impact positively on success. The Technology Acceptance Model (TAM) is one of the more widely accepted theoretical frameworks that has been used to measure system acceptance. This paper combines the TAM, as the theoretical framework, with case study research to provide a more holistic account of why a specific IS, an online assignment submission system, has become successful. Initial findings suggest that the TAM measures of perceived usefulness and perceived ease of use are effective predictors of systems success.