Abstract
The article presents a description of scientific achievements concerning Multiple-Criteria Decision-Making (MCDM) methods attained as part of the cooperation between scientific centres of Lithuania, Germany and Poland with a special emphasis on the input by Professor Edmundas K. Zavadskas and his scientific school. The cooperation, which commenced in 1986, focused on “Colloquia” — the systematic, international scientific seminars. The article aimed to summarise and popularise the achievement of these “Colloquia” in the area of MCDM as well as spotlight the outstanding theoretical and application significance of accomplishments by Prof. Zavadskas. Also, the work presents the most recent MCDM methods developed by Prof. Zavadskas that improve the accuracy of calculations and extend the area of their application.