LotBatch Number control each item

Please check 2pictures below  (Shop Order(above), Invenrty Parts Mater(lower)
    
As Shop Order created, how Lot/Batch No generated Automatically?    
LotNumber (right) has been generated to conbine    
     Order NO,"-", Rel,"-" Seq "-" with running number.  (See Shop Order screen)
    
But, please take a look the lower picture, Invenory Part master.    
You can find that Lot batch string can be defined as Prefix of Lotno when Manufacturing process.     
    
My Expect for lotbatch number is as  below in this practice.    
    
Lot batch no of “G-3081 18L” should be G-3081xxxx  (xxxx auto run number)    
Master could be completed, but why the lot no can noto be controlled.     
Please give me your advise.   
 

Regards;
Yasuda