SAP R/3 is placed on an applications layer on top of standard RDBMS databases, such as Oracle. It uses this infrastructure to provide a comprehensive set of business applications and tools. It provides support for human resource management, financial management, logistics operations and many other types of standard business functions. SAP supports three core APIs:

The SAP 4GL language for writing enterprise applications is similar to LotusScript and provides programmatic access to all of the SAP's standard functions. For example, to access financial or accounting information held in the SAP back-end tables, you could use ABAP/4 for writing a script.

This API is used for remotely addressing R/3's application transaction engine. For example, to remotely access a specific table or row of data within SAP's database, or log into the SAP system, the users can use a variety of standard RFCs. It also enables SAP developers to access RFCs. You can access RFCs using Notes or Domino using LotusScript and the SAP LSX implementing the ABAP/4 scripting language.

It is used for writing standard business objects such as server, function, table, row, row collection, transaction and field for R/3. The latest releases of Domino including 4.6 and 5.0 are offering a comprehensive set of integration tools for joining Lotus and SAP core systems. Presently, there are four primary approaches to integrating R/3 and Domino:

• A. LotusScript Extensions (LSX) for R/3
• B. Domino Connector for R/3
• C. Domino Mail Transfer Agent for R/3
• D. R/3 workflow-enabled Domino mail template

The approaches that are currently available to integrate SAP R/3 and Lotus Notes are:

Lotus Connectors are system files that are developed using common object model interface, known as Lotus Connector API. They provide optimized access to the enterprise data from Domino. These connectors are installed on the Web Application Server platform of SAP and are used to connect to and to transfer data from the enterprise servers and other enterprise platforms. This Lotus Connector, when used with enterprise integration tools, facilitates to integrate SAP application logic with Domino applications. The Connector was developed using SAP's Remote Function Call Software Development Kit (RFCSDK) and enables execution of any SAP Remote Function Call (RFC) that is remotely callable, all BAPIs and Transactions using Batch Data Input. Using the Lotus Connector for SAP technology ensures that data transfers and queries are processed through the SAP application layer, preserving the business logic and data validations contained in SAP Remote Function Call and transaction interfaces, which comprised of SAP processes. Therefore, reading and writing SAP data is always performed through the application layer and not by directly accessing back-end database tables and by using Lotus Connectors all the business rules provided by RFC’s and SAP Transactions are maintained.

A server-based add-ins, Domino MTA is used in bi-directional message transfer amid SAP R/3 and Notes, which leads to the transformation of Domino’s inbox into a universal inbox for both Domino and SAP. This tool is used to send messages to and from SAP R/3 to notes. It enables the users to send or receive mails, faxes and also disseminate the data from R/3 system to the notes mailbox. Hence, the users are required to check a common interface for reading the messages from both SAP R/3 and Lotus Notes. The Mail transfer Agent along with providing full attachment support provides users with the rich text support, facilitating R/3 mail users using any other application like Microsoft word as their e-mail editors. In addition, R/3 MTA provides all the transactional support that is required by the users. The users to make sure that the data being transferred from R/3 is properly routed to Domino can also use this support. MTA even enables the users to keep a track of all the messages that are sent or received from R/3 by tracking them in a Notes log file. As mentioned above, the Domino MTA uses add-ins. These add-ins are object client to send mail from Domino to R/3 and object server to receive mail from R/3.