Files with bcz suffix can be most often found as special exchange 'briefcase' files from Siemens PLM software.
BCZ file extension - Siemens PLM software ZIP BriefCase file
What is bcz file? How to open bcz files?
File type specification:
File extension bcz is related to Siemens PLM software and used for a support file format that Teamcenter uses for the offline GMS functionality. Probably some sort of archive.