Abstract: The increased attention given to information technology in the business environment has propelled information systems (IS) and IT Departments into prominent positions in many firms. Yet, little is known about how IT Departments exercise communications. The value of ISs is losing in IT Departments, which plays considerable role in the value chain from vendor to corporate customers. Poor communication effectiveness of internal IT departments has a bad influence on how IS will introduced and exploit. This paper addresses that gap through its focus on one research question: Who are the customers of the services IT Departments provide? In the paper, we use Electronic Document System consumption data as our model building samples and present a modeling framework for building segment-level predictive models that utilize pattern based clustering approach and signature discovery techniques. We devise fluctuate-rate matrix to study various modes. Through clustering on this matrix, we uncover different customer characteristics. Utilizing these characteristics, we can build two-dimension Consumption- Based customer segmentation model.