SAP PI is one of the core components of NetWeaver.It stands for Process Integration. Here is a list of important transaction codes used in SAP PI ABAP.
Administration Transaction codes
- SXMB_IFR: Start Enterprise Service Integration Builder
 - SXMB_ADM: Integration Engine Administration
 - SXI_SUPPORT: Test all Repository and Directory Objects
 - SMQR: qRFC monitoring to display the status of QIN Scheduler and Registration.
 - SMQ1: qRFC monitoring the Outbound Queue.
 - SMQ2: qRFC monitoring the Inbound Queue.
 - SLDAPICUST: Customizing API for System Landscape Directory.
 - AL11: SAP Directories Display to check the profile parameter DIR_TRANS.
 - SU01: User Address Maintenance
 - SICF: HTTP Server Configuration
 - RZ20: CCMS Monitoring
 - AL08: Logged in user list screen.
 - SM21: System Error Logs
 - ST22: ABAP Runtime Errors
 - SLDCHECK: Check the connection to the System Landscape Directory (SLD).
 - SM58: tRFC error Logs
 - SMICM: ICM Monitor
 - STRUST: Trust Manager
 - RZ70: SLD Administration
 
Web Services Transaction codes
- SUDDIREG: Maintaining UDDI Registry
 - WSADMIN: Administration tasks for Web services
 - WSCONFIG: Configuration of Web Services in the Web Service Framework
 - SOAMANAGER: Start SOA Manager
 - WSPUBLISH: Publish Web Services
 
IDOC transaction codes in PI
- IDX1: Assign Port (RFC destination) in IDOC Adapter
 - IDX2: IDOC Metadata administration
 - IDX5: IDoc tracking like display IDOC XML Messages
 - WE02, WE05: IDOC Display and IDOC list respectively
 
Business Process Management (BPM) Tcodes
- SWF_XI_ADM_BPE: Start and Stop BPE
 - SXMB_MONI_BPE: Monitoring tool for Business Process Engine (BPE)
 - SWF_XI_PBUILDER: Detailed BPM Process Builder
 - SWF_XI_CUSTOMIZING: Check Integration Process prerequisite
 - SWF_XI_ADM_BPE_DISP: Display the status of BPE
 - SWELS: Switch Event Trace On/Off
 
Monitoring transactions in PI
- SMGW: Gateway Monitor
 - SXMB_MONI: Monitoring Integration Engine
 - SXI_MONITOR: Monitor for Processed XML Messages
 - SXI_CACHE: PI Runtime Cache
 
