Information systems outsourcing takes diverse forms for various reasons. In order to analyze the diverse types of outsourcing relationships between outsourcing vendors and clients, two dimensions of outsourcing decisions proposed by Nam et. al. (1996), "the extent of substitution by vendors" and "the strategic impact of outsourced IS applications", are utilized as a framework. Four cells depicting types of outsourcing relationships are described based on the two dimensions. This paper studies the outsourcing experiences of four representative firms selected from 15 case study firms located in the U.S. within the framework of the proposed four types of outsourcing relationships. The movement of four firms in terms of its outsourcing decision within and across the cells is examined in order to derive the managerial guidelines over time.