"The WIP work order associated with this transaction is currently locked and being updated by another user"

One of the thing that causes this Lock is because "Inventory Manager" and "WIP Mass Load" are updating the same job. If you are submitting online IM (mtl_online_transaction_pub.process_online) to process material transactions inside your code and you got the lock message, you can solve it by checking the running concurrent request, if WIP Mass Load is one of them you keep looping till it's complete then you can run mtl_online_transaction_pub.process_online declare v_program varchar2(2000); -------------get all running concurrent requests cursor c4 is select substr(fcrv.program,1,40) program from apps.fnd_conc_req_summary_v fcrv where fcrv.phase_code = 'R' and fcrv.program like 'WIP Mass Load (WIP Mass Load)'; begin while 1 = 1 loop v_program := null; open c4; fetch c4 into v_program; close c4; if(v_program is null) then exit; end if; end loop; end; ------------------after that you can call mtl_online_transaction_pub.process_online