It is a fact that the impact of changes is more easily absorbed into the overall project earlier than later in construction projects. Most project schedules contain floats in the activities to absorb any potential schedule delays or impacts, and the project contingency is more likely available to cover additional costs associated with the changes. Later in the project, however, the schedule is more compressed, contingency has already been used, and there is less potential to mitigate the impact of changes by resequencing or accelerating work, reducing costs in other areas, etc. The figure illustrates the general relationship between the timing of changes and the ability to mitigate the impact of the changes on the project’s cost and schedule.

Increasing Impact of Late Changes