The VLA can be split in groups of antennas observing different sources and/or with different resources simultaneously, these are called subarrays.  There are some restrictions with the number of subarrays, the number of antennas in the subarrays, and how the subarrays may observe.  For details, refer to the Subarrays section of the Observational Status Summary and the VLA Observing Guide.

It is not straightforward to set up the PST for subarrays because the sessions cannot request a partial array.  Since each subarray will be a session, if the sessions have the total time for the subarray then total time requested in the proposal will be the total time multiplied by the number of subarrays.  The suggested work around is to divide the total observing time by the number of subarrays and use that as the time requested for each subarray session.  For details, please see the Subarray Observations section of the Guide to Proposing for the VLA.