How restaurant owners or managers can increase customer satisfaction?

A great way to increase customer satisfaction is to train all employees in your restaurant, from front to back of the house, this fundamental philosophy based on the simple acronym GUEST:
G-Greet, U-Understand, E-Educate, S-Satisfy, T-Thank:

       
Greet all guest cordially when they visit your restaurant. Understand their need, why they are there and exceed their expectations. Educate your customers on your menu and specials.  Armed with understanding of your customer, satisfy their needs. Then, thank them sincerely and welcome them back to visit your restaurant. 

Last and most importantly, always be gracious, courteous, and sincere with all your customers. There is nothing worse than a half-hearted, "See ya..." as the customer is leaving your restaurant.