The paper analyzes the application of expert system XpertRule Knowledge Builder when choosing glass products made by company Vetropack D.D. The task is supposed to describe the company Vetropack D.D., explain what artificial intelligence is and define the characteristics and properties of expert systems. It is also supposed to define the attributes of glass products for an expert system and with example show the application of an expert system and analyze its use and results. The theoretical part shows where is the company, its history and technology it uses during the manufacture of glass containers. It also explains the concept of artificial intelligence, its division, how it is examined and its development throughout history. There are also shown the characteristics and properties of expert systems and their areas of application. Experimental part shows an example of the application of expert system XpertRule Knowledge Builder when selecting glass products from catalog of company Vetropack D.D. Products are described with attributes through which a worker can, using an expert system, choose the product of specific characteristics requested by customer. It is also shown how the change of one selected attribute is affecting the choice of product. With the illustrated example of an expert system implementation it can be concluded that its application benefits company operations and although the technology still has drawbacks, the benefits it have points to its increasing use in the future.