Network scheduling techniques--such as the arrow diagramming Critical Path Method (CPM), Precedence Diagramming CPM, and the Performance Evaluation and Review Technique (PERT)--were developed extensively for the defense industry for control of their large government contracts. These methods have gradually been adopted by a segment of the construction industry, but they do not fulfill the criteria which a good scheduling system should meet. The objectives of this research include the development of a modeling approach that depicts the hard logic and alternative logic for project activities and the development of optimization functions for the scheduling model to minimize project cost at various levels of probability in achieving the scheduled completion date. In addition, a system as envisioned would require a unique database which currently does not exist. An objective includes the development of a specification for this database and methodology for database support.