How to configure Integration Directory for Integration process async sync

Question

Hi Experts,
                 I am confused about doing configuration in Integration Directory i.e receiver determination,interface determination and receiver agreement and sender agreement for my integration process as it involve synchronous send at target side.
In my Scenario , we get Purchase order request(asynchronously) from SRM system in proxy xml format which we have to map to Cxml format send it to third party system(say system 2) as http request.Then we will recieve a response from system2 in Cxml format through HTTP.Now,we have to map this response as to SRM system via proxy code for successful and error case .If error occured we also have to mail to the respective department about the error occured via mail adapter.Proxy to XI is a asynchronous communication and XI to System2 is a synchronous communication .Then again XI to SRM is a asynchronous communication via proxy.I have request and response External defination for Cxml i.e HTTP side.
I have done following integration process in ESR
Start- Receive(1)---Transformation(2)-send(3)-Fork(4)--
stop
...................................................................................................... .....[----Branch 1 [-Transformation(5)-Send(6)-
.......................[-----Branch 2 -
SWITCH STEP to check error code[
............................................................................................................[.otherwise branch of switch
Fork(4)----[
.......................[----Branch 1-Transformation (9)-send(10)-
Here,
Recieve(1) -- is used for recieve request from SRM.Mode is asynchronous
Transforamtion(2)-- is used for operation mapping between request of SRM to HTTP request.
send(3) --is used to sending request synchronous to HTTP,mode is synchronous,used synchronous abstract interface,abstract reqhttp and abstract resphttp
switch-switch Branch1 is used for checking error response to be true---
Transformation(5)--- is used to map HTTP response to Mail response structure
Send(6)----
is used to send mail content to Mail adapter
Transformation(9)---- is used to map HTTP response to Proxy response
Send(10) --- used to send mapped proxy response to SRM as to update status by calling calling Function module using proxy code.
Thanks
Deepak

Answer 1

Deepak,
In BPM data does not flow in Backword direction!
take any step in your BPM the message it is goiong to receive will be what a step just before it is giving to BPM.
Now in your case
IR Part:
You have to call Third part Synchronously and the input to it will be what Proxy has given to you.
Create an Abstract Synchronous(in case of abstract you need not bother it is Inbound or Outbound) in which(I mean the Message Interface) The Output message will be what you have Received from Proxy and the input message will be what you are going to receive from the Third party as a Response.  Now you would have Inbound Synchronous Interface created for calling Third party.
Have a Interface Mapping between the Abstract Synchronous and Inbound Synchronous Message Interface.
ID Part:
For synchronous Step:  BPM will; be sender with  Message Interface Abstarct Synchronous
Third Party will be receiver With Inbound Interface(Synchronous). Use the INterface Mapping between Abstract Synchronous and Inbound Synchronous that You have created in IR.
Have a Receiver Agreement for the Thirs part.
No Sender agreement required in case of BPM as a Sender.
Thanks,
Sunil Singh