Creating and Editing XSD Files 
An XSD (XML Schema Definition) file defines the structure of the data, which a data object contains. You create an XSD file if you want to set a data type that is different from the primitive ones to a data object.
You edit the XSD file to define the elements, types, attributes and groups of the XSD. For more information about XSD, see http://www.w3.org.
The data mapping in the process composer does not support all data types. For more information about all limitations on data types, see the SAP Note 1468084.
Prerequisites
You have opened the Process Development perspective in the SAP NetWeaver Developer Studio and have expanded your project in Project Explorer view.
Procedure
Creating an XSD File
Expand Process Modeling.
In the context menu of the Data Types folder, choose New XSD....
In the dialog that appears, specify a parent folder for the source file of the XSD and a file name and choose the Next pushbutton.
The XSD file appears in your project, in
the Process Modeling
Data Types XSD Files 
folder. The XSD source file appears in the parent folder you defined.
Editing an XSD File
Expand Process Modeling, then expand Data Types and XSD Files.
In the context menu of an XSD file, choose Open.
The XSD editor opens.
In the context menu of Elements on the Design tab page, choose Add Element.
Select an element under Elements and define its properties in the Properties view.
In the context menu of Types on the Design tab page, choose Add Complex Type or Add Simple Type.
Select a type under Types and define its properties in the Properties view.
In the context menu of Attributes on the Design tab page, choose Add Attribute or Add Attribute Group.
Select an attribute under Attributes and define its properties in the Properties view.
In the context menu of Groups on the Design tab page, choose Add Group.
Select a group under Groups and define its properties in the Properties view.
Note
You can also edit an XSD file on the Source tab page of the XSD editor and in the Outline view.