Repetitive projects are characterized by the presence of large number of repetitive activities, along with a number of non-repetitive activities. Each of thee two types of activities requires different scheduling techniques. Non-repetitive activities in the project can be scheduled using traditional network-based techniques such as the critical path method. Repetitive activities, however, require techniques that are capable of accounting, primarily, for crew work continuity. Integration of the two planning techniques, in an efficient operating environment, is the objective of the proposed model. The model accounts for two types of activities (repetitive, and non-repetitive), and three types of relationship (regular-relation, repetitive-relation, and hetero-relation). Object-Oriented Programming technique is utilized to design the different components of the model, in an effort to avoid the duplication in modeling, and benefit from the shared data and method elements among the different data types. The present model makes use of data encapsulation and inheritance concepts in order to develop a properly derived and organized hierarchy of classes. Such a hierarchy is designed to best represent the characteristics of the two types of activities and their relationships.