Resource driven.

See this response:



From Primavera:



P3 3.1

Driving resource means a resource that determines the duration of the

activity to which it is assigned. P3 automatically calculates the

activity duration based on the quantity to complete and the units per

timeperiod of the driving resource. P3 schedules independent and

meeting activities using the resource calendars of their driving

resources.

Defining a resource as driving or nondriving in the Resource Dictionary

only establishes its default status; you can change it for any specific

assignment.



P3e

A resource that determines the duration of the activity to which it is

assigned. The Project Management module automatically calculates the

activity duration based on the quantity to complete and the units per

timeperiod of the driving resource.



Defining resources as driving, by marking the Drive Activity Dates by

Default checkbox for new resource assignments in the Projects window,

Project Details, Resources tab, only establishes its default status;

you can change it for any specific assignment.



If an activity has more than one driving resource, the resource that

takes the longest to complete determines the duration of the activity.



Regards



Marcio Eduardo