Description of the Project 
Your work with LSMW starts with the definition of the project as a unit of the data to be migrated.
Process
You create the project from which you want to migrate data in the LSMW:
If
Then
The mapping and field assignments for a project are available in an SAP system (for example, test system).
You export them from this system and import them into your SAP system. See Exporting a Project and
The mapping and field assignments for a project have been stored on a data carrier.
You import them into your SAP System.
You want to migrate data from your legacy system for the first time.
You define the project.
You define the subproject for a project or make it known to the LSMW by importing the mapping and field assignments (see above).
Result
The project and subproject have been defined. Now you define the (business) object.