Estimating a project’s duration is rarely just a matter of adding up how long each task will take. The problem usually isn’t that someone misjudges a single task’s length. It’s that the estimate ignores how tasks connect to each other and how much capacity the team actually has.
Why estimates keep running late
Most teams estimate task by task: they look at how long a piece of work should take, then add those numbers together. This method overlooks two things.
The first is the effect of dependencies. If a task can only start once another one finishes, the project’s total length isn’t the sum of every task’s duration. It’s the length of the longest chain of tasks that depend on each other. We covered this in more detail in our article on task dependencies.
The second is available capacity. A task estimated at eight hours of work won’t be done in a single day if the person responsible can only spend two hours on it alongside other duties. Estimates often describe the amount of work, not the calendar time it will take to complete.
Task level or project level estimation
There are two basic approaches.
Task level estimation assigns time to each individual task, and the full schedule is built from these figures. This gives a more accurate picture, but only works well when tasks are small and clearly defined. Estimating a vague, multi week task is essentially guesswork.
Project level estimation starts from experience with similar past projects. If a comparable piece of work last took six weeks, the new project is likely to fall in a similar range. This is faster, but only works where a comparable precedent exists.
In practice, a combination of both works best. Estimate the project as a whole using an experience based range, then refine the estimates for the critical tasks individually.
What’s worth recording for the estimate
An estimate is only useful if you can later check how accurate it was. For each task, it helps to record the estimated effort in hours, the expected completion date, and the actual deadline. With this data available per task, patterns emerge over time showing which types of tasks consistently deviate from their estimates.
In MyPro Sync, these fields are part of a task’s planning data, and the Gantt view draws its bars based on the estimated hours, so planned and actual progress are visible in one place.
Why it’s worth building in buffer time
An accurate estimate doesn’t mean buffer time becomes unnecessary. The more tasks depend on each other, the higher the chance that at least one of them slips, and that delay carries through the entire chain. Buffer time is better placed at the project’s critical points, typically ahead of milestones that depend on multiple tasks, rather than hidden inside individual tasks.
If a task is a prerequisite for several other pieces of work, its estimate deserves extra attention, because a delay there won’t stay the problem of just one task.
Practical takeaway
A reliable time estimate isn’t a single number. It’s a range that accounts for how tasks connect and how much capacity the team genuinely has. Break work into small, well defined tasks, record both estimated and actual times, and place buffer time where the most tasks depend on a single point.