Despite the careful attention paid by managers and researchers to the effective administration of the S/W Development Project, there are cases where the project goes over-budget or misses deadlines. Existing research blames these problems on task complexity or mismanagement. In order to verify the results that varied according to the fitness between the Task Characteristics and the Project Management Types, a contingency model was employed. The verification of the contingency model demonstrated that the greater the task complexity, the greater the effectiveness of the project coordination, and the lesser the task complexity, the greater the effectiveness of project control. This research is theoretically important in that it develops a composite model to verify the relation between the three factors of Task Characteristics, Project Management Types, and Project Performance that compose the S/W Development Project.