For an overview over BW PCA, see http://scn.sap.com/docs/DOC-54097.To use BW PCA, you must own an SAP NetWeaver Landscape Virtualization Management, enterprise edition license. You can then either run BW PCA locally in ABAP task manager for lifecycle management automation or trigger it centrally from SAP NetWeaver Landscape Virtualization Management, enterprise edition.
A central entry point for all issues is the SAP Technology Troubleshooting Guide on http://wiki.scn.sap.com/wiki/display/TechTSG/%28PCA%29+ABAP+Post-Copy+Automation