SUMMARY
The purpose of this article is to describe the development of a knowledge-based system that, aided by rules, can support the decision-making processes of the sales department of a company. The knowledge-based system can bring reliability and agility to the decision-making process, and can allow for simulating future scenarios for the company, according to the combined behaviour of key variables. All variables identified in the study have some degree of importance for the decision-making process; they must be analysed together to produce a reliable answer, otherwise, an incorrect decision can emerge, damaging the execution of the company’s strategy. The main contribution of this study is a case report in which a knowledge-based system helped to find an adequate alternative to a business problem in the sales sector of a company in the south of Brazil.