What it means
A project plan may need eight designers on Monday and only two on Thursday, and some Monday work could start later without delaying any critical milestone. Smoothing uses that flexibility to make the workload more even.
Float is the amount a task can move before it delays a successor or the project finish under the chosen measure, and smoothing uses free or total float, as appropriate, without creating extra people or hours. MPUG explains the PMBOK distinction: smoothing adjusts resource demand within available float while preserving the critical path and project duration, whereas levelling balances demand and supply more broadly and can extend the schedule.
The two methods should not be used as synonyms. A simple fictional schedule has a five-day task that can start any time next week, and moving it from Monday to Wednesday might reduce a shared specialist's peak while the project end remains unchanged if the move uses available float.
The deadline constraint matters, because if every activity is on the critical path with zero float there may be no room to move work, and smoothing cannot solve a hard resource shortage by magic. Even where some float exists, the resource limit might still be exceeded in a peak, so a manager may need more capacity, changed scope or a different deadline.
Report the unresolved overload rather than showing an artificially clean chart. Smoothing can reduce idle time between peaks, and a steadier workload may help coordination and lower overtime, but its benefit should be checked against the actual cost of moving tasks and handoffs.
The shifted task may affect an intermediate milestone even if the final date does not change, so check customer reviews, supplier deliveries and dependent teams, because "on-time finish" is not the only promise that matters. Before moving a task, verify prerequisites, since a review cannot start before the draft exists and resource optimisation does not override logical dependencies.
A scheduling tool may pick a mathematically smooth allocation that clashes with worker availability, so confirm leave, shifts, part-time hours and required skills; a designer is not interchangeable with a specialist tester. The resource profile also needs a useful time scale, as a weekly view can hide a Tuesday conflict if two jobs require the same person for the same hour.
Moving work later consumes slack and leaves less room for future delays, and MPUG notes that smoothing can reduce scheduling flexibility even when it protects the current end date. A business might prefer to keep some buffer rather than use all available float, accepting a modest workload peak to preserve contingency, because the best trade-off is not always the flattest graph.
For a fictional marketing project, two design tasks overlap while one has three days of float, and moving that task by two days reduces the designer's workload peak but leaves only one day of float. Retain the baseline schedule for comparison, recompute if work slips in execution, coordinate across projects that share people and show the remaining float and any unresolved peak, escalating when capacity is genuinely insufficient (especially where the finish is a fixed public date) rather than assuming float will solve it.
In practice
Real-world examples.
Example
A flexible design task moves two days later to avoid overloading a shared designer. The finish date does not change, and one day of float remains. The planner records the new dates and tells the task owner.
Example
A project has no float, so smoothing cannot fix its specialist shortage. The manager reports the unresolved overload to the sponsor. The sponsor decides between extra capacity, reduced scope or a later deadline.
Example
A manager keeps one day of buffer rather than using every available slack day. The workload peak is slightly higher than the flattest possible plan. The team accepts that in exchange for protection against late supplier deliveries.
Formula
Calculation
There is no single formula. Shift eligible activities within available float so resource demand is less uneven while preserving the required project finish and dependencies. Remaining float after a move = float before the move - days moved.
Worked example. A fictional designer can work on one task at a time. Task A needs the designer on days 1 to 3, and Task B also needs the designer on days 1 to 3 but has 3 days of float. The overlap means 3 overloaded days (days 1, 2 and 3).
Moving Task B by 2 days puts it on days 3 to 5, so only day 3 still overlaps and the overloaded days fall from 3 to 1. Remaining float = 3 - 2 = 1 day. Moving it by the full 3 days would put it on days 4 to 6 and remove the overlap, but it would use all of the float and leave a remaining float of 3 - 3 = 0 days and no contingency.Case study
Seen in the real world.
In this entirely fictional case, Juniper Events has two overlapping design jobs and one designer. One job has three days of float, so the planner moves it two days later. The finish date stays fixed and one day of float remains. The team checks that its review meeting still has the required draft in time.
Watch out
Common mistakes.
- Assuming smoothing can fix a shortage when no float remains.
- Using all slack without noting reduced contingency.
- Ignoring intermediate handoffs because the final date stays fixed.
Questions
People also ask.
Does smoothing change the project end?
It is intended to keep the required end date and critical path unchanged.
How is it different from levelling?
Levelling may move the finish to respect resource limits; smoothing works within existing float.
Can a peak remain?
Yes. Limited float may leave some resource demand above available capacity.
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