Multi-project scheduling: A new categorization for heuristic scheduling rules in construction scheduling problems

After more than two decades of applying CPM as a planning and scheduling technique there is growing doubt about some of the advantages initially attributed to it. It is being discarded by both large and small construction companies, and its use limited to cases where it is required by the clients. Some planners and schedulers have begun to depend on their own experience. The author has developed a heuristic planning and scheduling model which uses two new criteria: the tightness degree of completion due-dates and resource tightness degrees. Throughout the scheduling experiments, the hypothetical relationship between the performance of the proposed heuristic scheduling rules and the degrees of completion due-dates and resource tightness proved to be correct and there is a significant difference between the performance of proposed heuristic scheduling rules in the different scheduling classes. The new classification of scheduling problems proved to be practical, effective and helpful. The scheduling experiments resulted in a new categorization for the performance of the proposed heuristic scheduling rules in the different scheduling classes.