Investments in Information Technology (I.T.) continue to grow, yet there continue to be doubts regarding the economic benefits of I.T. This paper researches prior work into what constitutes I.T. value and how I.T. creates value. Two general approaches predominate the literature on researching I.T. value - the micro economic production theory approach and the firm level process oriented approach. The micro economic production approach investigates the impact of multiple inputs (such as I.T. investment) on some output measure (such as productivity) using economic production theory techniques. This approach implicitly assumes usage of the I.T. investments. Because this approach fails to consider the usage of I.T. within the business, it lacks explanatory power in identifying how I.T. impacts firm level results. The firm level process oriented approach provides an explanation of how and why I.T. value is created because it considers I.T. usage in the business. This paper focuses on the process oriented approach and reviews prior work in this area. A comprehensive model of I.T. value building on prior work is presented.