Measurement units often have to be converted in applications. In multi-lingual systems, or with language-dependent measurement units, there is also the problem of displaying the relationships between measurement units correctly in the interface. For these reasons, SAP function modules are provided, with which all tasks which arise in connection with measurement units can be performed. The required information for each measurement unit is stored in a measurement unit table, which is accessed by the function modules for performing conversions.
This includes conversion exits, which perform an automatic conversion between external and internal format when using certain domains for screen input/output fields.
The function modules are buffered by default to minimize the number of database accesses needed for the conversion. The buffer is created at the first call of a module in each function group. This call therefore takes somewhat longer to complete. In general though, many modules in both function groups are used repeatedly, so that the effort of creating the buffer is justified.