The aim of this study is to develop a fuzzy inference model to
estimate the impact of change orders on the duration of
construction projects in Syria. This can help in obtaining the
optimal estimation of the increasing of the project duration caus
ed
by the changes. The capability of gradient estimation of the fuzzy
logic approach reduces the distrust of estimation using factor
assessment. Also it estimates the duration of the project after any
change.via the experts evaluation or according to the crisp logic.