About SCC7 - what is running?

Hello,

I have one question about SCC7.

Environment is

SAP : ECC 6.0

OS/DB : AIX/DB2

We tried client export and import to the same system/client, then executed SCC7.

It took only about 10 min. to execute SCC7.

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Source system: ABC

Target system: ABC

duration of SCC7: 10 min.

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When we did client import to another system/client, it took about 3 or 4 hours to execute SCC7.

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Source system: ABC

Target system: DEF

duration of SCC7: 3 or 4 hours.

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What would be done with SCC7?

I'd like to know why the execution time was so differnt.

Thank you very much and best regards,

Takae Momose