In this Ideas & Insights, we’re going to look at an issue that may arise when you are either preparing or reviewing a schedule update. In particular, we’re going to look at how your scheduling software may address “out-of-sequence” progress.
In construction scheduling, “out-of-sequence” progress occurs when activities begin, progress, and finish earlier than expected (based on the logic and activity durations in the latest schedule).
Oracle’s Primavera P6 Project Management (P6) scheduling software provides users with three different options with which to handle out-of-sequence progress. The Retained Logic and Progress Override options are carry overs from P3. However, there appears to be a significant amount of confusion among schedulers and construction professionals as to how the third option (Actual Dates) deals with out-of-sequence progress. Let’s look at how each of the three options deal with out-of-sequence progress in different situations.
To show how these scheduling options work, Figure 1 depicts a simple, four-activity schedule. The activities are connected to one another with Finish-to-Start relationships in sequence. Figure 1 illustrates how P6’s Retained Logic and Progress Override options deal with out-of-sequence when an activity begins earlier than expected and makes progress.
In Figure 1, the blue bars represent completed work, the red bars represent critical path work, and the green bars represent remaining work that is not critical. The dates identified in the schedule calendar correspond to the dates of the