How to see the origional scheduled ship date, before overriding

Summary:

Sales order can be rescheduled do to delays in various parts of the supply chain. If a customer care representive needs to change the scheduled ship date on the order, they should be able to store that original scheduled ship date to report on KPIs. Is there a way in the system that I can store the original scheduled date?

Transformation rules do not work since at the time of the order submission the SSD is not calculated. This needs to be stored after the scheduling task is completed.

Please advise.

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