Schedule Compression

The Full Picture

Schedule compression exists for the moment a project must finish sooner than the plan allows, an owner moves a deadline, permits eat the schedule, or early delays have to be recovered, and cutting scope isn't acceptable. The team has to find time inside the same work, which always comes at a price in cost, risk, or both.

Crashing adds resources to critical activities to shorten their durations: more crews, overtime, extra shifts, or additional equipment. It works only on the critical path (accelerating non-critical work buys nothing) and it hits diminishing returns as crowding and overtime erode productivity. The scheduler looks for the cheapest critical activities to crash first to buy time at the lowest cost.

Fast-tracking overlaps activities that would normally be sequential, starting foundations before all the design is complete, or beginning one floor's finishes while the next is still framing. It can save significant time but raises the risk of rework if the overlapped upstream work changes, because downstream activities committed on assumptions that later shift.

For preconstruction, compression decisions are shaped by what precon set up: how much design is complete, how procurement is sequenced, and where float exists. The key discipline is compressing the critical path specifically, and re-checking it after each move, since compressing one chain can make another chain critical. Blindly throwing resources at visible work wastes money without recovering the schedule.