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Handling of In-Progress and Completed Successors

Generally a successor activity will not start before its predecessor. It can happen, however. If it does, P3e ignores the relationship if the successor is complete and keeps the relationship if the successor has started but not finished.

By default PSOP will ignore relationships when the successor is complete and will ignore finish to start and start to start relationships when the successor has started but not finished. If you un-check ignore successor relationships to completed work option in the Primavera Compatability tab on the main window, PSOP will honor all relationships to started or finished successors.

For example, consider a project with two tasks, Write Manual and Publish Manual. Since the manual must be written before it can be published, there is a finish to start relationship and Publish Manual is a successor of Write Manual. Suppose that the Publish Manual task is somehow complete while the Write Manual task has not started; it is not clear how to handle the relationship. As P3e allows a task that is in the future to be started, it may still be possible to schedule the Write Manual activity such that the relationship is honored. In PSOP, if the ignore successor relationships to completed work option is un-checked in the Primavera Compatability tab on the main window, the relationship is honored if possible. Furthermore, if it is not possible to honor the relationship, PSOP will schedule the Write Manual activity as soon as possible. If the ignore successor relationship to in-progress work option is checked, PSOP will ignore the relationship and schedule the Write Manual activity at a time that minimizes the total schedule over-allocation and duration.

Note that in some circumstances it may make sense for a successor to start before its predecessor. For example, a project may have some paperwork that must be done close to the end of the project, but does not have to wait until the very end of the project. The Paperwork activity might then be a successor of the Last Task activity. There could be a finish to start constraint between the Last Task and Paperwork activities with a negative lag indicating that the paper work can begin before the last task is complete. In such a case the Paperwork might be in progress or finished before the Last Task had started.

We recommend leaving the ignore successor relationships to completed work box checked. If the successor was able to complete it generally means that the constraint was satisfied in practice and it thus does not matter when the predecessor starts.