Unplanned Service Parts Procurement in Service Order Management - Adhoc PO creation

[diwakarpsharma]

Hello Team,

I have spent some time on this and could not find whether this is currently possible in SAP.

Our client will use Service Order Management. As part of this process, they will procure Workforce. They would also want to be able to use the Service Order and perform unplanned procurement of Service Parts i.e. Create PO and assign Service Order as an account assignment to it manually. They will not plan for service part procurement in the service order.

I have read a few articles/documents from SAP, blogs, many notes and all of them talk about planned Service Parts procurement where we need to maintain Service Part in the Service Order which will trigger creation of Purchase requisition. 

While testing, I created a service order without service part. I then used it as a reference in the PO with account assignment category R, and system errors out saying reference item in service order is incorrect or is different than what is in the PO. 

Do we have an option create a PO with Service Order as an account assignment and assign a service order/item without maintaining the Service part in the Service Order, just like we can do it for Project (WBS) and Sales Orders?