Estimating Duration and Work in Microsoft Project

We recently received a question from a user regarding Work and Duration estimates. She wanted to know how to estimate both and let MS Project calculate the percentage of a person’s time that would be allocated to the task. In a nutshell, here’s how to accomplish this:

If you are entering estimates BEFORE you assign resources, follow the steps below:

1. Set your task type for all existing tasks and all new tasks to ‘Fixed Work’
2. Enter both the duration and work estimates for each task
3. Assign your resources

If you are making changes to an estimate AFTER resources are assigned, you need change the task type accordingly. The scheduling formula is Duration x Units = Work. If you change one of those variables, then project has to recalculate one of the other variables. So, if resources are already assigned and you need to change the DURATION estimate, follow the steps below:

1. Make sure the task type is set to Fixed Work
2. Change your Duration and the Work should remain the same, the units for the resource will change although you won’t see it appear on the Gantt Chart (to see the current assignment units go to the Resource Usage View and insert the column ‘Peak’)

If resources are assigned and you want to change the WORK estimate, follow the steps below:

1. Make sure the task type is set to Fixed Duration
2. Change your work estimate and the Duration should remain the same, the Units for the resource will change although you won’t see it appear on the Gantt Chart (to see the current assignment units go to the Resource Usage View and insert the column ‘Peak’)

Just in case you aren’t familiar with task types and how to change them….

For existing tasks:

1. Highlight all tasks you want to change
2. Go to the Task Ribbon
3. Click on the Information button
4. Select the Advanced Tab and change your task type

To set the task type for all new tasks:

1. File --> Options --> Schedule tab
2. You will see the option to change your task type for all new tasks

Learn more tips and tricks like this one by attending one of our webinars or training courses!

Happy Scheduling!

Related

• Microsoft Project 2010/2013/2016 Online Training
• 8 Steps to Scheduling Success–Step 3: Entering the Estimates
• Microsoft Project Training: Work vs. Duration
• Microsoft Project Training Webinar Series - Module 03a: Task Planning with Microsoft Project Part 1
• Microsoft Project Training Webinar Series - Module 05: Assignment Planning with Microsoft Project