Shariah supervisory board plays a great role in minimizing the non compliance risk , are bank in muslims country enable it to play this role?

Yes, to the best of my knowledge Shariah Supervisory Boards plays thier role at banks in muslim countries in efficient way.

As brother Waqayah mentioned, these banks are obliged to do so by law.  However, the practices will be based on country-based governance and regulations as well as the degree of enforcement. 

Yes Sharia Supervisory board should be able to play an efficient role otherwise they should not deserve to be in the baord.

islamic banks are obligated to do so by law.