Abstract: “The effectiveness of economic time series analysis is based on a synthesis of an abstract model with a high degree of adequacy with respect to the modelling of real economic system. Complex economics systems are difficult to define, difficult to measure and the human element is incorporated. In the real world the system´s relationships are more or less non-specific and vague. The suitable theoretical background for abstract formalization and utilization of vague phenomenon of such uncertainty is fuzzy set theory. In engineering practice wherever there is a need to reflect the effects of unmeasured disturbances and influences are often used the fuzzy models. Therefore, the basic principles of fuzzy linear modelling and identification are presented. The paper mainly presents fuzzy analysis of the selected variables under these specifically defined conditions. The time-trend and seasonal cycles including their possibility areas are calculated, expressed and commented.”

Keywords: complex systems, fuzzy number, fuzzy linear model, genetic algorithms, time series, GDP, construction production, agricultural production, unemployment, timetrend, seasonal cycle, possibility area