Float, also called slack, is the amount of time a task can be delayed without causing the project's scheduled completion date to slip. A task with five days of float can start up to five days later than planned, or run five days longer than expected, without moving the end date. A task with zero float is on the critical path — any delay immediately pushes the project finish by the same amount.
Total Float vs. Free Float
Total float is the total delay a task can absorb before it affects the project end date. This is the number most project managers mean when they say "float."
Free float is narrower: the delay a task can absorb before it delays its immediate successor, regardless of the project end date. A task may have five days of total float but only two days of free float if its successor has only two days of scheduling room before it must start.
Both values come from the backward pass of the CPM calculation. Total float = latest start − earliest start. Free float = earliest start of the successor − earliest finish of the current task.
Float Is Shared, Not Owned
Float belongs to the chain of tasks between two endpoints, not to any single task in that chain. If Task A and Task B are in sequence, each showing five days of total float, using three days of A's float consumes three days of the shared pool — B's total float drops to two days as well. A project manager who aggressively starts every non-critical task at its earliest date uses up float before it is needed, eliminating the buffer that would have absorbed a later disruption on the critical path.
Deliberately leaving float intact on non-critical tasks is a legitimate risk management strategy. It keeps options open for when the unexpected happens on the critical path and you need to reallocate resources quickly.
Float in Maverick
Maverick calculates total float for every non-critical task and makes it visible on the Gantt chart as the gap between the task bar's right edge and the latest point at which the task could end without affecting the project finish. Critical tasks show no gap. The critical path recalculates in real time, so float values update immediately whenever you modify the schedule.
Related Terms
Critical Path · Task Dependency · Project Baseline · Gantt Chart
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