Multi-criteria decision analysis (MCDA) methods have become increasingly popular in decision-making. Numerous methods in this field were developed to solve real-world decision problems including various engineering and scientific areas. Unfortunately, the proper use of each method is difficult due to the dispersion of the domain knowledge and lack of knowledge databases in this area. The paper presents research focused on knowledge management aspects in MCDA domain. In order to achieve a high level of practicality on different levels of decision making, the ontology as a form of conceptualization is implemented.