It needs to have a list of everything you need. Note that the word everything here comprises of the equipment, technology, raw materials, financial and other resources that you may need when starting and running your business venture. Having all these listed will give you an idea on how much capital you need before you start and how much money should you make in a day to make your business survive.
Set out a basic management structure outlining who has responsibility for various aspects of the business. This will be easy in the beginning but eventually you may have marketing staff, administration staff, kitchen staff and servers. Make it clear how you plan on delegating tasks, leadership and responsibility for decision making down to your employees.
In essence, here is a great way to think of superior business planning. Imagine you are taking a road trip from California to New York. No planning ("flying by the seat of your pants") would involve you getting in the car and driving "East" on every freeway you come across. Adequate planning would involve mapping out your course, planning where to stay overnight, where to eat, sights to see, and so forth.
Moreover, while unpredictable issues will certainly always arise, effective business planning will not only help you to navigate the predictable operations, but will also take these unpredictable situations into account. This will help you to deal with these issues with a level of comfort and ease, knowing that you have thought through and planned for such events.