Variation in the use of clinical resources, outcomes, costs, access to health care and quality is a well recognized, ever present feature of health care. It is a phenomenon that affects all sectors of the health care delivery process and is important to clinicians, administrators and patients. As a phenomenon variation can be appropriate or inappropriate and the elimination of inappropriate variation is a fundamental principal behind continuous quality improvement in health care. The primary tools for the management of variation exists within the electronic medical record (EMR). The EMR utilizes the existing and evolving information storage technologies (data repositories) and information management tools (applications), to integrate the elements within this long-term data storage. Through this integration the EMR systems are able to provide knowledge representation in differing formats to the decision-makers and this will facilitate more accurate and appropriate decision-making with subsequent improvements in health care delivery.