Research on the implementation of Product Lifecycle Management (PLM) has been published since the beginning of the 21st century. Some researchers claim that the success rate of PLM implementation projects is below 50%, but the authors have found no evidence of that figure. In this paper's research, a number of PLM implementation cases have been analyzed for their project goals, implementation challenges, and project results. The research data are retrieved from project files and interviews with project managers. The investigated implementation cases are in Small to Medium-sized Enterprises (SME). The results have been structured and compared with findings from the authors' earlier literature research on SME specific implementation challenges and recommended implementation methods. From this comparison, a conclusion is drawn regarding the implementation success rate and a hypothesis for causes of observed failure.