Integration of SAP R/3 and Lotus Notes is brought about by using many approaches such as Lotus Enterprise integrator (LEI) and Lotus Connector. Lotus Enterprise Integrator, a Lotus tool for server-to-server data management is considered as "the middleware" for connecting and transferring or synchronizing information between Lotus Connector enterprise sources on a scheduled or event-driven basis. Lotus Enterprise Integrator (LEI) should be positioned as complementing the live access capabilities provided by Domino Enterprise Connection Services (DECS). Supporting high volume data exchange or synchronization, LEI consists of three components:

• A Domino Application also called as the Lotus Enterprise Integrator Administrator database.
• The LEI Server processes instructions, connecting to external data sources and moving data according to Activity defined conditions.
• An LEI Server Log, which records data transfers and error messages.

The Lotus Enterprise Integration technologies link Domino applications to a wide variety of existing enterprise systems in customers' environments. This comprises of connectivity to popular relational databases such as Oracle and DB2, as well as Enterprise Resource Planning (ERP) systems like SAP R/3 and PeopleSoft.

Undoubtedly, the integration of Lotus Notes with SAP R/3 is perfect. Focusing on high-volume and high-reliability transactional applications, SAP R/3 is a client-server system. On the other hand, Lotus Notes and Domino provide a general-purpose infrastructure for distributed enterprise database applications and messaging services.

These integration approaches are broadly classified into two classes viz. End-User Interface and Developer Tools.

End-User Interface enables the end users to analyze, enhance and distribute R/3 report data by using both the SAP R/3 and Lotus Notes.

Developer tools are the links given to the programmers to build applications in order to associate R/3 to Notes. In this approach developers are provided with Business Application Programming Interfaces (BAPIs), which are used as R/3 business objects by the Notes developer, so as to ensure this link up.