Recommended Technologies by SAP for Integration

Seamlessintegration across business applications has always been a critical area ofinterest for any organization. The criticality of application integration isobvious from the fact that this is often a critical factor in purchase decisionmaking.

SAP recommends the followingtechnologies for integration:

1. SAP BAPI (Business Application Programming Interfaces)
2. Remote callable function modules (RFMs) that have been released forcustomer / external use
3. IDocs (Intermediate Documents) provided by SAP, that are sent orreceived by mySAP Business Suite components
4. Data Transfer Programs provided by SAP

1. SAP BAPI (Business ApplicationProgramming Interfaces)

BusinessApplication Programming Interfaces (BAPIs) are standard SAP interfaces thatenable software vendors to integrate their software into the mySAP BusinessSuite. BAPIs are technically implemented using RFC (Remote Function Call)enabled function modules inside SAP systems.

BAPIs aredefined in the Business Object Repository (BOR) as methods of to SAP businessobjects that perform specific business tasks. They allow integration atbusiness level, not technical level. This makes it much easier to find suitableBAPIs compared to non-BAPI based function modules.

Once SAPhas released a BAPI, its interface definitions and parameters will remainstable in the long term, which means third-party application programs will notbe affected by changes to the underlying SAP software or data. If upward-compatibleenhancements are made to the BAPIs, the integration of the existingapplications is not affected. If incompatible changes to the BAPI becomenecessary, SAP will create a new BAPI and mark the old BAPI as "obsolete".Obsolete BAPIs are guaranteed to work at least in two subsequent functionalreleases, starting with the one in which they are declared obsolete. This givesdevelopers approximately two years, depending on SAPs release cycle, to changetheir existing integration from using the obsolete BAPI to the usage of the newBAPI.

2. Remote Function Call

The SAPdevelopment environment supports several ways of structuring software. ABAPfunction modules are equivalent to what most programming languages call "functions".The SAP system contains thousands of function modules - for example more than110,000 in SAP R/3 release 4.6C.

Only asubset of those can be called from external systems using a protocol calledRemote Function Call (RFC). RFC allows for remote calls between two SAP systems(for example SAP R/3 and SAP BW) or between an SAP system and a non-SAP system.These remotely callable functions are called RFC-enabled function modules orRFMs in short. SAP R/3 release 4.6 C for example contains more than 10,000RFMs. They can have import and export parameters to send and receive databetween systems. Only RFMs with a 'released for customer/released for externaluse' status will remain stable in long term. Only these should be used forthird-party integration projects and are eligible for interface certification.As the special set of RFMs that are linked as methods of the business objectsin the SAP systems, BAPIs are explicitly released for customer usage.

3. Intermediate Documents

Intermediate documents (IDocs) were originally invented by SAP to supportElectronic Data Interchange (EDI) in a generic fashion. Later, IDocs were alsoused in the SAP Application Link Enabling (ALE) technology as data containers,which allow exchange of business information between an SAP system and otherSAP or non-SAP systems.

IDocs arebased on a hierarchical, tree-like segment structure. The syntax for each IDoctype is defined in the SAP system. IDocs can be used in the following businessscenarios: ? ?Application Link Enabling (ALE): Communication between logicalsystems (intra-company relations).

Logicalsystems can be either SAP systems or non-SAP systems. ALE distribution modelsare based on message types and BAPIs that indicate the appropriate IDoc types.? ?Electronic Data Interchange (EDI): Communication between SAP systems and the3rd party EDI subsystem which is typically connected to an EDI VAN(inter-company relation).

IDocs arecreated when message types and (object) methods are distributed. The messagetype is the semantic information which identifies the usage of business data.The IDoc type defines the syntactical format in which the data for a specificbusiness process is transferred.

4. Data Transfer Programs