Hi Sankarsan,
That is correct shift A do 28 days then go on leave on day 29 when shift B arrives.
Shift B work days 29 to 56 then shift A come back and shift B go on leave.
The person in shift in Shift A and Shift B are both doing the same job (department supervisor for example) but each works for 6 months of the year to ensure that the role is covered for the full 12 months.
I know there is a section in SAP for shift planning but we are currently unable to access it due to the way that our system has been structured.