applying value engineering through fuzzy madm approach to improving project performance

one of the most effective tools for decline cost and time, quality improvement and consequently project performance enhancement especially in construction projects, is value engineering. there are linguistic judgments in many cases of value engineering studies in construction projects such as interior design, mechanical installations design, and etc. therefore multiple attribute decision-making techniques with fuzzy approach can be used in decision-making stages in value engineering process. in this paper, value engineering is combined with fuzzy madm techniques. in this hybrid, fuzzy ahp technique is used in order to determine the weight of evaluation criteria recommended in creativity phase and fuzzy topsis is used for ranking of alternatives. this approach was applied in design phase of mechanical installations of mouj tower project in sadaf town, one of the under construction projects in :union: sector of the state. according to the paper results, estimation of value engineering team, leads to 21.45 % of decreasing in project’s costs and 17.65% of decreasing in project’s duration.