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The Sign-Off Table

Lesson 1 of 5

Integration technologies

10 min

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An SAP S/4HANA system rarely works alone. Orders arrive from customers, purchase orders leave for suppliers, payments go to banks, and a web portal asks for order status every few seconds. Each of those conversations runs on an integration technology: an agreed way for two systems to exchange data. If you test, design or support SAP, you need to recognize the main technologies on sight, because each one fails, is monitored and is tested in its own way.

This course uses Contoso Motor Co. as its running example. Contoso is converting its SAP ECC 6.0 EHP 8 system to SAP S/4HANA Private Edition (systems CMD, CMQ and CMP). Its integration lead, Theo, owns an inventory of about 60 interfaces that must keep working on the day after go-live.

The six technologies you will meet

TechnologyWhat it isTypical use at Contoso
IDoc (Intermediate Document)SAP's structured document container for business messages, with a control record, data records and status records. Usually exchanged asynchronously.Inbound sales orders from Great Lakes Fleet Services over EDI; outbound purchase orders to Lakeside Components
RFC / BAPIRemote Function Call lets one system call a function module in another. BAPIs are released function modules that represent business object methods, such as creating a sales order.An older shop-floor system in Detroit posts confirmations by calling a BAPI
ODataAn open REST-based protocol (an OASIS standard) for reading and changing data over HTTP, with a published metadata document.Contoso's customer portal reads order status; SAP Fiori apps use OData behind every screen
SOAP web servicesXML messages over HTTP described by a WSDL contract. SAP S/4HANA offers many SOAP APIs, often for asynchronous business-to-business messages.A tax or logistics partner exchanges XML documents with a fixed contract
EventsA short notification that something happened ("business partner changed"), published to a broker that delivers it to any subscriber.Planned: notify the portal when a delivery is posted instead of the portal polling for it
FilesA batch of records written to a file and moved by a transfer protocol on a schedule.Bank payment files and daily bank statements; a nightly price list for a distributor

The main integration technologies in an SAP S/4HANA landscape.

SAP groups the remote interfaces it supports into released APIs: OData services and SOAP services for synchronous and asynchronous calls from outside the system, plus events for event-driven communication. IDocs and BAPIs are older but still heavily used in on-premise and Private Edition landscapes, especially after a system conversion, which carries existing interfaces over.

Contoso's landscape after the conversion: each partner reaches SAP S/4HANA through a different technology, and most traffic still passes through SAP Process Orchestration.
The Sign-Off Table · thesignofftable.com/academy/sap-int-101
Business messageWhat is exchanged: a sales order, an invoice, a payment, a status change
Format and contractIDoc type, OData metadata, WSDL, event schema or file layout
ProtocoltRFC for IDocs, RFC, HTTPS for OData and SOAP, a message broker for events, SFTP for files
PlatformDirect connection, SAP Process Orchestration or SAP Integration Suite in between
Every interface can be described in four layers. Testers who name all four rarely miss a failure point.
The Sign-Off Table · thesignofftable.com/academy/sap-int-101

How to tell them apart

In practice you identify a technology by where its traces appear. An IDoc has a number and a status history you can read in transactions such as WE02. An RFC call leaves entries in the RFC destination configuration (SM59) and, if it is transactional and fails, a queue entry. An OData call is an HTTP request to a URL under /sap/opu/odata/ or /sap/opu/odata4/, with an HTTP status code and an error log. A SOAP message is logged in the web service monitoring. A file has a name, a timestamp and a record count.

TechnologyStyleWhere you see it failTypical tester check
IDocAsynchronousIDoc status (for example 51, application document not posted)Status 53 and the posted document in the app
RFC / BAPIUsually synchronousReturn messages; RFC errors in the calling systemReturn table has no errors; the document exists
ODataSynchronousHTTP status 4xx or 5xx and the gateway error logCorrect status code, payload and data change
SOAPSync or asyncSOAP fault or web service monitor entryResponse or acknowledgment, then the posted document
EventsAsynchronousUndelivered event at the broker or subscriberSubscriber received the event and acted on it
FileAsynchronous batchMissing file, wrong count, rejected recordsRecord counts and totals match source and target
Each technology fails in a different place, so each needs its own monitoring and its own evidence.
The Sign-Off Table · thesignofftable.com/academy/sap-int-101
One business flow, three interfaces: an inbound ORDERS IDoc, a synchronous OData status call and an outbound INVOIC IDoc, each with its own evidence.
The Sign-Off Table · thesignofftable.com/academy/sap-int-101

What would you do?

Priya, the test lead, asks Theo for the interface list for the first integration test cycle. Theo's spreadsheet lists each interface by partner name only ("Great Lakes orders", "Bank statements"). What should Priya ask Theo to add first?

Key points
  • The main SAP integration technologies are IDoc, RFC/BAPI, OData, SOAP web services, events and files.
  • Describe every interface in four layers: business message, format, protocol and platform.
  • Each technology fails and is monitored in a different place; tests must collect evidence there.
  • A system conversion carries existing IDoc and RFC interfaces over, so they stay in scope for testing.

Check your understanding · not graded

Lesson check

  1. 1. Which record in an IDoc tells you the sender, receiver and IDoc type?

  2. 2. A customer portal asks SAP S/4HANA for a list of open orders over HTTPS and gets JSON back. Which technology is this most likely to be?

  3. 3. Why do IDoc and BAPI interfaces stay in scope after a system conversion?