Although the causes for project success and failure have been the subject of many studies, no conclusive evidence or common agreement has been achieved so far. One criticism involves the universalistic approach used often in project management studies, according to which all projects are assumed to be similar. A second problem is the issue of subjectiveness, and sometimes weakly defined success measures; yet another concern is the limited number of managerial variables examined by previous research. In the present study we use a project-specific typological approach, a multidimensional criteria for assessing project success, and a multivariate statistical analysis method. According to our typology projects were classified according to their technological uncertainty at project initiation and their system scope which is their location on a hierarchical ladder of systems and subsystems. For each of the 127 projects in our study that were executed in Israel, we recorded 360 managerial variables and 13 success measures. The use of a very detailed data and multivariate methods such as canonical correlation and eigenvector analysis enables us to account for all the interactions between managerial and success variables and to address a handful of perspectives, often left unanalyzed by previous research. Assessing the variants of managerial variables and their impact on project success for various types of projects, serves also a step toward the establishment of a typological theory of projects. Although some success factors are common to all projects, our study identified project-specific lists of factors, indicating for example, that high-uncertainty projects must be managed differently than low-uncertainty projects, and high-scope projects differently than low-scope projects.