Hi @wael_abdelwahab - PAM is not replacing SAM right now. There are some similarities between the two products (i.e. both have password vaulting) but PAM has many other capabilities that are not offered in SAM. Some examples are cloud and virtualization protection (VMWare, Amazon AWS, Office 365), command line filtering, and SSH key management. PAM also offers very high time to value as it's packaged in either a physical or virtual appliance.
Customers can continue to renew on CA Privileged Identity Manager and CA Shared Account Manager. At some point in the near future we will offer an upgrade option for customers who want to upgrade from SAM to PAM.
Hope this helps.
Mike