Improve Your Project Task Duration Estimates

Accurate task duration estimates are a primary building block of a realistic and dependable project schedule. But teams sometimes get estimates from end users and other stakeholders that are incomplete or contain flawed data. This can lead to big scheduling problems later.

task duration estimates

How can you get better task duration estimates? It isn’t just up to those doing the estimating. There are ways PMs can also improve the quality of the information they receive. We’ve put together some tips to improve the process.

One common problem is that those doing the work don’t understand what you need from them. Step back and examine what you’ve asked for in past projects and compare that against the data you’ve received. Is it possible you’re getting inaccurate estimates because your requests are confusing? In many cases, the people providing task duration estimates aren’t familiar with the ins and outs of project planning. They may not be skilled at separating the concept of a final completion date from a more generalized timeframe that identifies the amount of time a task will take.

The solution is to be very clear about what you need from stakeholders. If you want a firm calendar date for the completion of each task, tell them that. Conversely, if you’re looking for an activity’s length from beginning to end, spell that out so stakeholders can give you what you need.

Next, consider if stakeholders are prioritizing being nice over being accurate. One problem that crops up again and again is the desire to please. It’s simple human nature. People typically like to make other people happy. Unfortunately, this tendency can result in task duration estimates that are not only inaccurate, but are much too optimistic to be useful. When a pleasing answer—rather than an honest one—is given, the project team is likely to find itself mired in delays and resource conflicts as things move forward.

To avoid this issue, let people know early on that you don’t want an answer that sounds good. Instead, emphasize your need for estimates that are accurate, even if that means finding out that a task’s expected duration will require the team to resequuence other nearby or dependent activities to another spot in the schedule.

Along with setting very clear expectations about what the project team needs with regards to task duration estimates, it’s critical that PMs give people adequate time to develop accurate estimates. Like most aspects of project management, reliable task duration estimation isn’t an instantaneous process. Your stakeholders may need time to conduct research or other legwork, which could include requesting information from vendors, confirming availability of in-house resources or tools, and ensuring they’ve included all of a task’s necessary steps in their estimate.

Finally, the team needs to be sure they’re asking the right people for task duration data. Querying a department head, for example, won’t always yield the best estimates. Unfortunately, PMs too often try to make project planning less cumbersome by engaging as few people as possible in the process. This approach causes more headaches than it solves, with results that range from mere frustration to all-out project failure.

Instead, work with stakeholders to identify additional people who should be involved in the task duration estimation process. This could range from front-line workers to outside vendors, depending on the nature of the tasks. These individuals may not need to participate in the bulk of the project planning efforts, but gathering their insight on their activities’ more granular data can make the difference between a reliable, usable project schedule and a timeline that’s sure to go off the rails.


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