1. RFC
2. EDI
3. ALE
4. IDOC
5. SAP enhancements / user exits
a. Menu Exit
b. Field Exit
c. Customer Exit
d. Function Module Exit
6. BAPI
7. BADI
8. WORKFLOW
9. WS UPLOAD
10. CLASS BUILDER
11. Background Processing
12. Job Scheduling
13. Object-oriented programming with ABAP Objects:
- classes and objects
- Inheritance
- Interfaces
- Events
- Exception handling
- Persistent objects