Perfect Analogy to understand PI/PO Design Objects-ESR.

[khusal810]

Hello Integration Aspirants,

When I started learning about middleware and SAP PI, it was difficult for me to understand the use of different objects. But then I came across a perfect real-life analogy that I am bringing to you via this blog to better understand PI/PO Objects. In this blog, we will learn about ESR Objects. ID Objects will be discussed in the next blog.

But first, let’s have a small introduction to middleware.

Middleware is a technology that is used to transfer information from one program to one or more other programs in a distributed environment and making it independent from the communication protocols, OS, and hardware used.

In SAP World, SAP PI is used to connect various SAP and non-SAP System. 

Now that we know what SAP PI does? Let us discuss the main object or the high-level Object which PI refers to always. This is called Interface.

The interface is a device or a program enabling two or more systems, subjects or organizations to meet or interact.

A real-life example of Interface is our touchpad on a mobile screen or keyboard on our laptop. It is an interface between us and underlying software.

In SAP PI, Interface is designed to transfer messages from one system to another system.

Now let us begin the most interesting part of this blog.

The real-life analogy of Interface is just like sending a letter to your friend who is staying in some other country.

Now let's break this letter sending and view its analogy with SAP PI Interface Designing Objects.

1. Data Type: Suppose I want to write a letter to my friend staying in the US. I will write my content on a piece of paper. This is the actual intended data I want to send to my friend. Thus whatever actual data I need to send to other applications is called Data Type.


2. Message Type: Now after writing my letter I will place it inside an envelope. As the letter is not sufficient to send and we need an envelope. The same way data type is encapsulated inside the message type.


3. Service Interface: Next on the envelope I will write the address of the receiver and sender. So that the Post Office knows where this letter has to go. The same way to determine which operation/interface is determined with the help of service Interface. 


4. Message Mapping: Now you have your letter ready you put in the P.O.Box near you. The Postman will pick up and letter and take it to the Post Office. Here Post Office is the real-life middleware ( analogy to SAP PI/PO). Once your letter is received by the Post Office. It will determine which route the letter will be sent depending on the address of the receiver. Suppose the letter is to send a very long distance. It will be sent in stages. For example, if the letter is to be sent from India to the United States. It will be first transferred to say first France then later to the United States. This transfer can be seen as a Message Mapping. Although, the message mapping in PI is used for transforming messages rather than mere transferring.


5. Operation Mapping: In SAP PI, an operation mapping establishes the connection between source and target operation from service interfaces of sender and receiver systems, respectively. Thus transferring letters from India to the United States can be seen as operation mapping. Just as explained earlier an operation map can contain more than one message map.

PI Analogy

I hope this analogy will help you relate and understand PI ESR Objects.

In the next blog, I will discuss the IB Objects in detail.

Please provide your feedback.

Take Care and Stay safe during this COVID Pandemic.