To get processes not working on ERPs to work, I typically do not try to change the ERP's source code.   That can lead to bigger disaster.
I solve it by using the "Sakamoto ERP Solutions" which consists of the following steps:

1) Data Warehouse (DW) that has the ERP data and many other data, especially data missing from the ERP.

2) Analyze the problem, develop solution.
      * This is the key. IOTW designs the solution by using my experience in Accounting, MBA, IT and in particular Auditing.

3) Program and create the designed solution.
     * You can have your IT department create it, or IOTW can create it.

I typically run the solutions through a separate web site controlled by the client.  It works closely with the ERP but can do more since its controlled and customized by the client and uses the Data Warehouse (DW), which contains all of the ERP data, plus additional data that the ERP does not have.   I typically do not try to modify the ERP program code and add the new solution to the ERP program.   That often results in disaster.