PBO and PAI are two events used for designing the screens in SAP ABAP Module Pool Programming. Every Dynpro screen has a set of PBO and PAI modules.
Note: One PBO & One PAI allowed for a Screen
What is PBO Event?
PBO (Process Before Output) determines the flow logic or execute modules before displaying the screen. This event is used for displaying the fields from the program to the screen. User can build the GUI status in PBO.
Example of PBO
PROCESS BEFORE OUTPUT.
MODULE INIT_FIELDS.
Self-programmed F1 Help
Important T-codes of PBO
| T-code | Des | Functional Area |
| SE51 | Screen Painter | BC - Screen Painter |
| SE80 | Object Navigator | BC - Repository Browser |
| SE38 | ABAP Editor | BC - ABAP Editor |
| ABAPDOCU | Display ABAP Documentation | BC - Syntax, Compiler, Runtime |
| FMOD | Override FM Update Date | PSM - Funds Management |
| SMOD | SAP Enhancement Management | BC - Customer Enhancements |
| ME21N | Create Purchase Order | MM - Purchasing |
| FMRP_RFFMTO30X | pboF - Ann.Bdgt vs Cmmts/Acts Totals | PSM - Information system |
| ME32K | Change Contract | MM - Purchasing |
| CMOD | Enhancements | BC - Customer Enhancements |
What is PAI Event?
PAI (Process After Input) determines the flow logic execute modules after the display of the screen and after receiving inputs from the User. This event is used to write the code for the User actions on the screen. In PAI data moves from screen to program.
Example of PAI
PROCESS AFTER INPUT.
* Lock customer master record
CHAIN.
FIELD GSSG-KTNRG
MODULE ENQUEUE_CUSTOMER_MASTER.
Important T-codes of PAI
| T-code | Des | Functional Area |
| SE51 | screen painter | BC - Screen Painter |
| SE80 | Object Navigator | BC - Repository Browser |
| SE38 | ABAP Editor | BC - ABAP Editor |
| SE11 | ABAP Dictionary Maintenance | BC - Dictionary Maintenance |
| SMOD | SAP Enhancement Management | BC - Customer Enhancements |
| ME21N | Create Purchase Order | MM - Purchasing |
| SE37 | ABAP Function Modules | BC - Function Builder |
| DBG_SCREEN_PAINTER | Debugger -> screen painter | BC - Syntax, Compiler, Runtime |
| SE41 | Menu painter | BC - Menu Painter |
| MIGO | Goods Movement | MM - Inventory Management |