We can get the documentation of EMIGALL in SAP,
Go to Transaction EQ81
Some points about EMIGALL :
1. It Migrates data Business Object wise
2. It uses Direct Input Technique
3. It has more than 100 objects of IS-U
1)Create a user specially for migration which will have all the authorizations related to migration workbench, BASIS and IS-U
2)Create your own company in EMIGALL. There is a default company called SAP.
3)Company SAP contains all the Business Objects
4)Figure out what business objects u need and then u have to copy those business objects to ur company from Standard Company SAP
5)Each objects contains more than one structure and each structure can contain more than one fields. The relation goes like this
Object ---> Structure ---> Field
6)Define field rules for each required field of the object. You have to mark "Not required" for fields u don't need
7)After field rules for a given object is set u have to generate load report i.e. actual Direct Input Program which will migrate data. This program is generated on basis of field rules set by u.
8)After the load report is generated u have to prepare an input file (import File) for migration. The import file should be according to structure provided by SAP and must be in binary format. SAP Provides the structure of file according to your configurations. You have to write ur own Data conversion program(in any language) for this task.
9)Import file as input and migrate the data using generated load program
10)Finally check the Migration Statistics and Error Log