Abstract :
The development of information technology has helped humans in various fields of life, one of which is in the field of business which is used by business people to increase competition between competitors. one of them in terms of marketing their wares. Even though they have been used to compete with each other, there are still business actors who have not been able to take full advantage of information technology developments. One of them is at D'Terrace Valley Cafe, a cafe that serves a wide variety of food and drink menus at affordable prices. In marketing the menu offered, the cafe still uses the traditional method, namely when offering a menu that does not have a reference, it is still based on estimates. Even though the cafe has taken advantage of existing technology, although its use is only limited to making weekly and monthly sales reports, it is not maximized. Even so, if used properly, these transaction data can be processed as information in solving various kinds of problems and can be used in developing future business strategies. Therefore, we need a support system that can provide a reference in offering menus properly and precisely. This support system uses data mining techniques using association rules and a priori algorithms. The a priori algorithm has several advantages, namely, it is simple and can handle large data. After carrying out the calculation process on 131 transaction data with a minimum value of 6% support and 50% minimum confident, it produces 5 association rules that can be a reference or guide for cafes in making business strategies, both in marketing or other matters.