The system landscape for CRM or any SAP Module USUALLY looks like this:

A) Development system (here you do all customizing settings and developments).
B) QA (quality ASSURANCE system): for end user TRAINING and ESPECIALLY for unit testing and integration testing purposes.
C) Productive system.

SAP CRM is for example usually integrated with a backbone SAP R/3 system. Integration in this case happened via the CRM middleware. On both sides (R/3 = plug in and CRM you will have a R/3 adapter).

For integration with BW there exists a BW Adapter. (In the CRM system, SAP delivers by the way STANDARD data sources that can be used by the BW system. They can be activated (content) and replicated to the BW System for data analysis.

The system landscape for CRM or any SAP Module usually looks like this:

A) Development system (here you do all customizing settings and developments).
B) QA (quality assurance system): for end user training and especially for unit testing and integration testing purposes.
C) Productive system.

SAP CRM is for example usually integrated with a backbone SAP R/3 system. Integration in this case happened via the CRM middleware. On both sides (R/3 = plug in and CRM you will have a R/3 adapter).

For integration with BW there exists a BW Adapter. (In the CRM system, SAP delivers by the way standard data sources that can be used by the BW system. They can be activated (content) and replicated to the BW System for data analysis.