It ensures that:

• Users see data in a friendly, understandable format (e.g., formatted dates, leading zeros removed).
• System stores data in a standardized internal format (for consistency and integrity).

How It Works

When a domain is assigned a conversion routine:

• At input (user to system): the routine converts external input to internal format.
• At output (system to user): the routine converts internal format to user-friendly format.

Example

Domain: MATNR (Material Number)

• Internally: Stored as 18 characters with leading zeros, e.g., 000000000000123456
• Externally: Shown as 123456 to the user

Conversion routine: ALPHA

• Input: Adds leading zeros to match the length
• Output: Strips leading zeros for display
  

  Type	Value
  External	123456
  Internal	000000000000123456

  How to Assign a Conversion Routine

  1. Go to SE11 → Choose your domain.

  2. In the conversion routine field, enter the routine (e.g., ALPHA, CONVERSION_EXIT_ALPHA_INPUT/OUTPUT).

  3. Save and activate.

  The actual logic resides in function modules:

  • CONVERSION_EXIT_YYYY_INPUT

  • CONVERSION_EXIT_YYYY_OUTPUT