(If the image is too big, you can read the original article at this link : https://doduykhuong.com/2018/03/25/how-to-use-activity-duration-type-in-primavera-p6/ )

In Primavera P6, when we assign resource to activity there is a equation:

Original Duration x Units/Time = Total Units

(          10 days        x 8 hours/day = 80 hours         )

Now when you change duration, which element will be changed: Units/Time or Total Units?

That's when Activity Duration Type come in to play.

The above equation must always be true.

The Duration Type rule determines which field has the most importance (value will be fixed). Below is a matrix that identifies which fields are recalculated based on the Duration type.

• If the duration is fixed, P6 will never recalculate the duration.
• If the duration is not fixed, P6 will always recalculate the duration.

Let's do some exercise to understand it.

Fill in the columns in the table below so that the equation remains true.

Duration Type: Fixed Units/Time

Duration Type: Fixed Units

Duration Type: Fixed Duration & Units

Duration Type: Fixed Duration and Units/Time

About the Author : Khuong Do

Khuong Do is a Project Planner / Scheduler in Civil Engineering, Transportation, and Oil & Gas Industry. He has worked as a Primavera Consultant Specialist since 2006 and willing to share his passion for Primavera through lots of Tips & Trick on his personal blog : https://doduykhuong.com