Some Important Transaction Codes in SAP

User Administration:
SU01- User Maintenance
SU01D- User Display
SU02- Maintain Authorization Profiles
SU03- Maintain Authorizations
SU05 -Maintain Internet users
SU10 -User Mass Maintenance
SMLG- Maintain Logon Group
SUPC -Profiles for activity groups
SUIM -Info system Authorizations
PFCG -Profile Generator
PFUD- User Master Data Reconciliation
Client Administration:
SCC3 -Checking Client Copy Log
SCC4 -Client Administration
SCC5 -Client Delete
SCC7 -Client Import Post-Processing
SCC8 -Client Export
SCCL -Local Client Copy
SCC9 -Remote client copy
Database Administration:
DB01- Analyze exclusive lock waits
DB02 -Analyze tables and indexes
DB12 -DB Backup Monitor
DB13 -DBA Planning Calendar
DB15 -Data Archiving: Database Tables
Transport Management System:
STMS -Transport Management System
SE01 -Transport and Correction System
SE06 -Set Up Workbench Organizer
SE07 -CTS Status Display
SE09 -Workbench Organizer
SE10 -Customizing Organizer
SE11 -ABAP/4 Dictionary Maintenance
SE16 -Data Browser
SE80 -Repository Browser
SM30 -Call View Maintenance
SM31 -Table Maintenance
Background Jobs Administration:
SM36 -Define Background Job
SM37 -Background Job Overview
SM39 -Job Analysis
SM49 --Execute External OS commands
SM62 Maintain Events
SM64 -Release of an Event
SM65 -Background Processing Analysis Tool
SM69 -Maintain External OS Commands
Spool Administration:
SP01 -Output Controller
SP11 -TemSe directory
SP12 -TemSe Administration
SPAD -Spool Administration
Other Administration Tcodes:
AL11 -Display SAP Directories
BD54 -Maintain Logical Systems
OSS1 -Logon to Online Service System
SALE IMG -Application Link Enabling
SARA -Archive Management
SICK -Installation Check
SM14 -Update Program Administration
SM35 -Batch Input Monitoring
SM56 -Number Range Buffer
SM58- Asynchronous RFC Error Log
SM59 -RFC Destinations (Display/Maintain)
SAINT -SAP Add-on Installation Tool
SPAM -SAP Patch Manager (SPAM)
SPAU -Display modified DE objects
SPDD -Display modified DDIC objects
ST11 -Display Developer Traces
Daily monitoring TCodes:
AL08 -Current Active Users
SM12 -Display and Delete Locks
SM13 -Display Update Records
SM21 -System Log
SM50 -Work Process Overview
SM51 -List of SAP Servers
SM66 -System Wide Work Process Overview
ST22 -ABAP/4 Runtime Error Analysis
ST01 -System Trace
ST02 -Setups/Tune Buffers

ST03 -Performance, SAP Statistics, Workload
ST04 -Select DB activities
ST05 -Performance trace
ST06 -Operating System Monitor
ST10 -Table call statistics
SU56 -Analyze User Buffer
Other Monitoring Tcodes:
OS01 -LAN check with ping
RZ01 -Job Scheduling Monitor
RZ03 -Presentation, Control SAP Instances
ST07 -Application monitor
STAT- Local transaction statistics
Other Useful Transactions Codes
AL22 -Dependent objects display
BAOV -Add-On Version Information
SA38 -ABAP reporting
SE38 -ABAP Editor
HIER -Internal Application Component Hierarchy Maintenance
ICON -Display Icons
WEDI -IDoc and EDI Basis
WE02 -IDoc display
WE07- IDoc statistics
WE20 -Partner profiles
WE21 -Port definition
WE46 -lDoc administration
WE47 -Status Maintenance
$TAB -Refreshes the table buffers
$SYNC- Refreshes all buffers, except the program buffer