Hi Lingannag,

Thanks for writing to PSC. Please find the details for your query as below:

When you want to transfer data from parent case to child case,  we can use the Data Propagation option to set the values in the subcase(s). The Data Propagation option can be found on the Details tab of the Case Designer. To propagate data from the parent case to the subcase, we click the edit link next to Data Propagation, to open “Case Designer: Data Propagation” dialog box. 

If we are simply taking the data without making any changes, we can use the data propagation option. We do not have to select “Also apply Data Transform.” If we are using the data conditionally or looping through a page list or if we need to reuse propagating data from parent to the subcase, we can use the “Also apply Data Transform,” option as well.

If the data from the parent case changes after the data has been propagated to the subcase during the instantiation of the subcase, the data change is not reflected in the subcase.  If the latest value of a property of the parent case is needed, then we use a data transform rule to get the value just before the processing of step/flow/shape of the subcase.

As per your example what ever initial value X have in parent case is propogated to child case. To update the value of X with latest modification happened, you have to use "Data transform rule".

I hope this explanation answer your query.

Thanks:

Gurpreet Kaur