IREP is a wonderful repository of all service endpoints or say compilation of all integrations for Ebiz suite.
From R12 onwards it even helps deploy web services.
But I can't seem to understand how in R11.5.10 could IREP help to deploy a web service. If the idea is to access IREP from Jdeveloper within a BPEL or ESB project then that is a separate thing and is recommended.
In 11.5.10 it appears otherwise IREP just provides a generic WSDL that is not specific to a particular Application instance since irep in 11.5.10 doesn't ship with the install.
How can one deploy a web service in 11.5.10 from IREP?
You have to read XML gateway documentation to get an idea for this. R11.5.10 gives you a generic WSDL for you to supply to your web service subscribers. I was able to enqueue a message successfully through BPEL by utilizing the WSDL supplied by R11.5.10 instead of using an AQ or Oracle Adapter.
The functionality of IREP is much more exploited in R12 compared to 11.5.10 and my personal beleif is that from R12 onwards it is of much use. Look at R12 IREP documentation. You will need to log in as sysadmin or with integration repository admin priveledge to deploy the web service but you can see it through other users as long as the resp is assigned to you and you can deploy XML Gateway and Service Beans based web services from with in R12.
for irep in 11.5.10
only interfaces of type "Web Service" can be directly invoked from external systems as it is already deployed and you can see the wsdl url.
for other interfaces such as PLSQL, XML Gateway, Business Events, ... etc, you should Developer a BPEL process using JDeveloper, and use the EBS adapter to access the irep and invoke whatever you want.