There are many factors that contributes to the success of a business, from how and where the establishment is located to one's managerial skills. But the three main factors that one should really consider before starting a business like a restaurant are:

• Supply and Demand + Target Audience

There is a reason why the Law of Supply and Demand  is taught in business courses. Simply because it works. Before starting out a restaurant business, you must first see to it that whatever you are trying to sell is in-demand or will be in-demand in that area. You must first know your target audience.. 

As an example: Before you start building a Japanese Restaurant in an urban area, you must first conduct a small research about the people living in that area. Do the people living there like eating raw foods such as sushi? How many of those people have the ability to buy and eat in a restaurant? If the result of your research is positive, then conduct again another research on how well can you acquire the materials/foods needed for the business. If you can't cater to the demand, chances are your business will suffer.

• Quality and Affordability

It is not surprising that one factor that contributes to the success of any businesses is the quality of the product or services being sold. In a Restaurant business, this is usually determined based on the quality of the food, how delicious the food you are trying to sell is. 

However, it is not always about the quality. As per the example above, people living in an urban area might not be able to afford some of the menus in the restaurant. No matter how delicious your food is, it's all moot if no one will buy it. Thus Quality along with Affordability is the key in here.

• Services Provided

I have been to so many restaurants before and one thing that made me not visit again some of them is how they treat there customers. The success of a restaurant business does not stop on the quality of the food but will continue on to the people selling the food, the Services of the restaurant. A restaurant with a friendly atmosphere usually ends up with lots of loyal customers going back to their establishment.