Hi Bala,
This happened only one time in one year. I have unlocked the users and after this I haven't noticed any incorrect locks from two days.
Audit log SM20 is not active so can't see details.
We use SAP Authentication in BOBJ.
I've never seen users password locked automatically for few users only. so, thought anything to do with process chains but our bw team says nothing ran during that period.
Regards,
Salman