Managing System Landscape Information 
A system landscape description is required by different SAP Solution Manager applications, like Monitoring and Alerting, diagnostics, and to calculate updates and upgrades with the Maintenance Optimizer.
For introductory information about modeling SAP system landscapes for successful maintenance, see the Maintenance Planning Guide at http://scn.sap.com/docs/DOC-29495.
SAP Solution Manager collects and stores detailed information about the system landscape, for example:
technical system information
product system information, for example usage and relationships between technical systems and the software installed on them.
This information is mainly based on the software descriptions in the SAP software catalog (SAP CR content) and on the information that is sent automatically by technical systems via the System Landscape Directory (SLD).
The SAP Solution Manager Landscape Management Database (LMDB) is the central landscape information repository. It uses the same standard (the Common Information Model, CIM) as the SLD to represent system information.
A technical system description in the LMDB has the following prerequisites:
Up-to-date CIM model and SAP CR content in the SLD that is connected to the LMDB.
Active synchronization between the LMDB and the SLD.
All technical systems register themselves in the SLD.
Some SAP Solution Manager applications can require additional configuration, such as the grouping of technical systems.
Do not create and edit technical system information manually. For more information, see Managing Technical System Information.
In contrast to technical system information, product system information must be created manually because it is not provided automatically.
Information flow from technical systems to SLD, SAP Solution Manager, and SAP Global Support Backbone (SAP Service Marketplace)
Most of the system information in the LMDB is provided by synchronization with a System Landscape Directory (SLD) in the system landscape, which continuously gathers data sent by the SLD data installed on the technical systems. Smaller amounts of information in the LMDB are created manually. Some data suppliers, such as SMD agents (Outside Discovery) write directly into the LMDB.
The LMDB was introduced with SAP Solution Manager 7.1. If you upgrade from SAP Solution Manager 7.0 to 7.1, the LMDB is mandatory.
As of SAP Solution Manager 7.1, information about technical systems, databases, and hosts is maintained only in the LMDB, and no longer in SMSY. For more information, see SAP Note 1679673.
As of 7.1 SP05, product system information is also managed in the LMDB.
As of 7.1 SP09, logical component information has also moved from SMSY and are integrated in the new LMDB UIs.
For more information, see the release notes at 
http://help.sap.com/solutionmanager 
Application Help select release and language Changes and New Features in SAP Solution Manager 7.1 SPxx SAP Solution Manager Operations 
.
Activities
System landscape management comprises the following tasks:
Setting Up the LMDB Infrastructure, including connecting the LMDB to one or more SLDs and migrating system information from transaction SMSY to the LMDB, which is required if you upgrade to SAP Solution Manager 7.1 SP5.
Managing Product System Information, including landscape verification.