Rebuildable Number is getting changed instead of Rebuildable serial number

Hi

I got one requirement , User want to have same Rebuildable number , and they want to change Rebuidlable serial number .

Like i create Work Order for Parent Boiler BA0001 and Rebuidlable number CPump 01 is attached CPump01 has serial number P0008.

If CPump01 has failure client will replace P0008 with P0009 my Rebuildable Number remains the same . I used standard functionality

for replacement of pump , i have take miscellaneous receipt P0009 and then issue to parent work order. in this transaction Cpump01

is completely removed and new Rebuidlable Number is created automatically. we dont want this happen we want to change only serial number not to change