Chaitanya,
I don't know exactly what your client wishes to automate. I hope he does not expect that SAP has some magical way to detect that an employee is missing, and then automagically reschedule the shop floor accordingly. Normally, someone has to 'tell' the system somehow that resource availability has been reduced.
The normal way you address capacity shortages (e.g. an employee does not show up for work) is by using Capacity leveling functionality. Capacity leveling can be automated by running Mass Processing batch jobs..
Capacity Leveling (PP-CRP-LVL) - SAP Library
Best Regards,
DB49