In Primavera P6, there are 2 popular activity type: Task Dependent and Resource Dependent.

So what is the difference?

By choosing Task Dependent or Resource Dependent, P6 will choose what calendar it will use for the activity:

• Choose Task Dependent: P6 use Activity calendar for the activity
• Choose Resource Dependent: P6 use Resource calendar for the activity

Then it will affect the Original Duration and Finish Date of the activity.

We have Activity A with attribute as below:

• Working duration is 10 days
• Activity Calendar is 7 days / week

• This activity is assigned resource R who work 5 days / week

Now if we choose Task Dependent, P6 will use Activity Calendar. Then activity duration will be 10 days. Activity Finish Date is 24-Mar-18

If we choose Resource Dependent, P6 will use Resource Calendar. Then activity duration will be 14 days. Activity Finish Date is 28-Mar-18

The process of calculation to have 14 days is as below:

When we assign resource to activity, it copy the value 10 days from activity duration to resource duration. Then it base on 5 days workweek to calculate Resource Finish Date.

Then it will mirror Resource Finish Date to Activity Finish Date. Then it base on 7 days workweek to calculate Activity Duration.

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