4 Tutorials that teach Time and Effort Estimates
Take your pick:
Time and Effort Estimates

Time and Effort Estimates

Author: Jeff Carroll
This lesson provides and overview of estimating the time and effort required to complete a project.
See More
Introduction to Psychology

Analyze this:
Our Intro to Psych Course is only $329.

Sophia college courses cost up to 80% less than traditional courses*. Start a free trial now.


Source: Image of clock, construction man with helmet, construction man without helmet, arrow, woman at laptop, Public Domain, Images by Video Scribe, License held by Jeff Carroll; Image of man working silhouette, calendar, Creative Commons, Kelly Eddington.

Video Transcription

Download PDF

Hi, I'm Jeff. And in this lesson, we'll discuss how a project manager gathers estimates on time and effort in order to create the schedule. The project manager will request estimates on each task from all the resources assigned to the task. It's important to ask all members since variation and expertise among the team might result in significantly different estimates for the time and effort involved.

When estimating effort, each team member should provide the amount of work required to complete their assigned tasks or activities. These estimates are usually provided in hours. And team members should be allowed to cooperate and ask for a consultation when they're creating the estimates.

Project managers should remember that team members with less experience will often need longer than those with greater experience, and might need more assistance coming up with accurate estimates. The project manager should assist with the estimation effort by compiling information from past projects that contain similar work. In the case of projects with poorly defined processes or work that's new to the organization, the project manager should also note that estimates might be highly speculative. And additional time should be added to account for this.

Time should also be estimated in addition to effort. Time estimates are their duration of actual time it would take to complete a task. And time estimates are impacted by the availability of a resource, dependencies, and by the amount of effort expected to complete the task.

For example, if the effort estimate on a task is 8 hours, but the resource is only available for 50% of the day, the time estimate will be two days, since they can only work four hours per day. And if the dependency leading into the task has a lag time of one day, then the total time to complete the task would increase to three days. It's the project manager's role to teach people about these impacts, and to document them clearly so everyone understands how the workflow will proceed.

One method used to estimate time or effort on a task is the average estimate. For this method, the project manager asks a team member to give two estimates-- the least amount of effort or time the task might take, and the greatest amount. The two values are then averaged and the estimate is used in the schedule.

For example, let's say that the project manager asked a team member to estimate the effort needed to program a quiz onto a web page. The lowest effort estimate is 5 hours. And the greatest effort estimate is 12 hours. The project manager then adds the five hour and the 12 hour values together and divides by 2 to come up with 8.5 hours. This is the estimate the project manager then places in the schedule.

All right, nicely done. You've now learned how to estimate the time and effort needed to complete tasks and activities in a schedule. And you've learned how to use the average time estimate method. Thanks for listening. And have a great day.