saiPackager.cmd is a tool that could be used to create a package from user.zsai files. The resulting package afterwards could be imported into UCMDB. This tool is used in UCMDB 10.0x.
Please note that in UCMDB 10.10 this tool is no longer available, as there is a new UI feature "Software Library" that has a function "Import SAI file", which can be used for this purpose. So saiPackager tool is no longer necessary and therefore it was removed to avoid duplicate entries from the user.zsai files, which could potentially cause issues.
However, there is a reference to to "saiPacker.cmd" in the UCMDB 10.10 JMX Reference Guide, stating that this file should exist in the folder C:\hp\UCMDB\DataFlowProbe\tools\. Please note that this is a documentation defect, which has already been acknowledged and will be corrected in a future Documentation release.