We have encountered a strange problem during launch form for OPA using Siebel data adapter. The launch form of OPA takes lot of time around 15 to 20 minutes sometimes. but If we bounce SR broker of Siebel this time reduces to 5 to 8 seconds. After some time of continuous use we3 again see the time interval rising and it is only after the SR broker bounce this time reduces looking at the log it seems Siebel becomes slow and it takes a huge time to send back across the web service response.
This must have something to do with Siebel starting up inbound web services. When you start web determinations with data pre-seeded from Siebel. OPA must call back to an Inbound web service in siebel to get the data.
If the inbound web service is not responding correctly this can take some time.