Acceleration
Deliberately compressing a project schedule, such as through added crews, overtime, extra shifts, or resequencing work, either to recover from a delay or to finish earlier than originally planned, usually at extra cost.
Why it matters
Speeding up a schedule almost always costs money: overtime pay, more equipment, more supervision to manage bigger crews, so acceleration is a real financial decision, not something a contractor does for free just because a project is running behind.
On a real project
A framing subcontractor falls three weeks behind schedule. To recover the time before it affects the overall project finish date, they add a second shift and work Saturdays for a month, billing the extra labor cost as an acceleration cost to whoever is responsible for causing the original delay.
Who this matters most to
A Superintendent plans and manages the actual acceleration effort in the field, coordinating extra crews and shifts without creating new safety or sequencing problems. A Scheduler models different acceleration options and their schedule impact so the project team can decide which approach recovers the most time for the least added cost.
Where this goes wrong
A general contractor accelerates a schedule to recover an owner-caused delay, assuming the extra cost will simply be reimbursed later. Without documenting the acceleration as directed or agreed to in advance, the owner disputes the added cost after the fact, arguing the contractor chose to accelerate on its own, turning a straightforward schedule recovery into a costly dispute over who has to pay for it.