This book presents a structural model of information system implementation and tests using data from several independent system implementation efforts. The model is based on the results of 15 years of implementation research and integrates the two primary streams of that research: factor studies and process studies. Testing the model involved three studies in diverse implementation contexts. The tests provide strong support for some aspects of the model and identify areas where the model is in need of further development and testing. The book includes a detailed review of past implementation research, a thorough explanation of the basis for the structural model's mathematical properties, descriptions of two field tests of the model including details about the research instruments employed, and a discussion of the utility of these studies for implementation research and practice.