Circular Relationships is one of the small mistakes we may make while assigning relationships. However, it has a very big impact on scheduling as Primavera will not be able to calculate the end date of those activities as we have created a circle among those activities. We need to identify that activity which is creating that circle so that the system can calculate and we can have correct date.
Below is the example :-
In above image, A1010 is successor for A1000, A1020 is successor for A1010, A1000 is successor for A1020.
Once we have added the relationships then we will schedule the project and it will show is the message as below :-
After looking at the pop up closely we would see that A1000 is creating circular relationships as it is starting again after A1020 has ended as per the relationship. We can go back and remove the relationship between A1000 and A1020. The Primavera P6 will then be able to calculate the end date of those activities and schedule the project.