@deepakrv: The documentation URL you have pasted is of SEARCH hospital. There we had deployed EMR, OpenELIS, and OpenERP. So, for them, the documentation for more assertive on the process to follow, since they would charge customers for lab tests done, and billing for done in OpenERP. For OpenELIS and OpenERP to sync, the data should be the same in both.
Please see this discussion: (Default) workflow between OpenMRS and OpenELIS
If you don’t want to use OpenERP, you don’t need to worry. You can use just EMR, and OpenELIS.