How to deal with Internal tables in Export/Import

As per thumb rule, Internal table should be similar( attributes) for both Export and Import Internal table.

How ever I have in program A, Program B.

Program a has internal table itab, and moving to Program B through Export/Import.

I have internal table Jtab named after Itab,

But question is if someone making changes to Itab, how to make sure this will reflect in Jtab?

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