I called the service with soapui directly at the service endpoint of ECC system and got the same long response time as with PI.
At PI-Monitoring it looks like the long response time is caused by ECC system.
I never worked with SPROXY. I have permission to start it. But when I go to "Enterprise Services Browser" -> ProductionOrderSimpleByWorkCentreQueryResponse_In
then I get "You don't have permission ...
At the ECC system, I'm using, there is no load.
Other SAP enterprise services respond within 1s.
There is an individual coded ABAP Proxy at the same ECC system, which finds same information within 1s. Our SAP Team want's to reduce the amount of individual code. That's why I'm trying to get the production orders with SAP enterprise Service.
Our SAP Basis gyus don't know SAP enterprise Services.