Advanced Mapping Techniques 
Besides simply mapping the values and structures of a message, your application scenario may require you to also use additional mapping techniques. This section summarizes the options that are currently supported.
Prerequisites
You are experienced user of one or more types of mapping program (message mappings, XSLT, or Java).
Features
Function libraries enable you to reuse user-defined functions in message mappings and mapping templates.
Parameterized Mapping Programs
You can increase the number of possible applications for a mapping program by using import parameters, or you can transfer values to an integration process by using export parameters.
References Between Mapping Programs
You can also use mapping programs in different program types.
You can use a multi-mapping to map one or more source messages to one or more target messages.
Adding Lookups to Mapping Programs
You can use mapping lookups in a mapping program to call functions in an application system.
Developing Mappings with ABAP Workbench
Customers can also develop mapping programs with ABAP Workbench.