If you are running services and P6 on the same server, you should keep the defaults. If you have recalculate assignment cost work that needs to be done immediately, you should set the Interval low (e.g., 10s) and the Concurrent Threads high (e.g., 20). Remember that if the server is actively running recalculate assignment cost work, all users will experience delays in the application.
To set your recalculate assignment cost settings:
Open the Primavera P6 Administrator.
In the Configurations tab, expand your configuration.
Expand Services/Recalculate Assignment Cost.
In the Interval field, enter the amount of time the RecalculateAssignmentCost service will wait before scheduling the next available job (in 1d1h1m1s format - specifying only numbers without letters implies milliseconds). When P6 initiates the RecalculateAssignmentCosts service, it will attempt to run immediately but switch to running as a job service if it takes too long to start.
The default is 10s.
Enter anything from 1s-24d20h31m23s647.
In the Concurrent Threads field, enter the number of processes used for the RecalculateAssignmentCost service on this server. A value of 0 indicates that the service is not available on this server.
The default is 2.
Enter anything from 0-20.
In the Active Mode field, choose true if you want jobs processed continuously until all jobs finish. Choose false if you want each job processed according to the Interval.