Hi Naresh,
Best advice is to stay right away from the SRM workflows - they are very detailed patterns. There are BADI controlled workflows, which use ABAP code in BADIs to determine the approvals, and Process Controlled workflows which use BRF or BRF+ (depending on the release level) to determine the approval levels and approvals.
Strongly recommend you start by reading the SRM Library help for your SRM release, and check if anyone on your site has already determined whether to use the BADI or the Process Controlled approach.
Regards,
Jocelyn
