The following document shows whether you can do a rolling upgrade (R) or offline upgrade (with the cluster down - O):
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02242562/c02242562.pdfI recently helped a customer go from one bundle to a different bundle where, in the above document, there was no path for the migration.
If you find that you need to migrate to a different bundle entirely, please consider opening a help case with the HP Support Center for guidance.
If you have an software contract, inspect "HP-UX Serviceguard - SMS Bundle Upgrade Procedure" (Document ID: emr_na-c02618741)